jimmymcgoochie

Like this:

*boop*

Like this:

*boop*

Like this:

*boop*

I don't see anything particularly wrong with those screenshots.
Using scatterer alone is unusual, try adding EVE (Environmental Visual Enhancements) and a set of configs for it- EVE has a set of default configs available or there are other mods such as AVP and Spectra that have their own. Scatterer adds atmospheric and ocean effects, EVE adds things like clouds and aurorae as well as (in some cases) textures for towns and cities on the surface of Kerbin complete with lights at night.

Aerobraking at Eve can save you a lot of delta-V, but it is definitely not for the faint-hearted due to the very high (>4km/s) velocities involved which will incinerate almost anything other than a heatshield. If you can do ISRU refuelling at Gilly, I’d say do that instead of risking an encounter with Eve’s atmosphere.
I just did an Eve landing as part of a Grand Tour and this is what it took to keep the thing pointing straight:

(Ignore Ike in the background…)

Download ProbesPlus master branch from the GitHub (link on the forum page or via CKAN) and not the release which is very out of date.
If that doesn’t work, post logs please:
https://forum.kerbalspaceprogram.com/index.php?/topic/83212-how-to-get-support-read-first/

Screenshots please?
To my knowledge, SVE is pretty old and if you’re using newer versions of things like EVE and scatterer (and KSP) then try a different visual pack like Spectra or AVP instead?

Download ProbesPlus master branch from the GitHub (link on the forum page or via CKAN) and not the release which is very out of date.
If that doesn’t work, post logs please:
https://forum.kerbalspaceprogram.com/index.php?/topic/83212-how-to-get-support-read-first/

Without any specifics it's very hard to give you any concrete answers. Screenshots of your rocket in the VAB with (MechJeb!) delta-V displayed and a link to said video would help the most.
There could be a number of reasons why you're getting less delta-V than the video:
Different versions of KSP/RO/related mods like RealFuels. Not so long ago some additional realism was added in the form of engine residuals- fuel in the tanks that the engines can't use- which means you'll lose a little bit of burn time when acceleration is greatest and so has a disproportionate impact on delta-V. Other variations exist between different versions of mods and even between versions of KSP. Vacuum versus surface delta-V. Atmospheric delta-V is always lower because the air gets in the way of the rocket exhaust, reducing ISP and thrust; you might be looking at surface delta-V whereas in the video it's showing vacuum delta-V. Different engine configs. Most engines in RO have more than one available config to reflect upgrades and improvements to the engines made over time. If you're using the first available config for the engine but the video is using an upgraded one with better stats, that could explain the lack of delta-V. Different fuel tanks. There's more than one type of fuel tank in RO and they can make a huge difference to delta-V: balloon tanks are the lightest and have the highest mass fraction (ratio of wet:dry mass) so give you the most delta-V, then integral structure tanks, then separate structure tanks, then service module tanks; this is further complicated by the different materials that can be used for each tank type -some of the best separate structure tanks will outperform early integral tanks- and by tank pressurisation for pressure-fed engines such as the AJ-10 which adds a lot of dry mass. Make sure you're using the proper tanks. Different propellants and ratios. The RD-0105, RD-58, F-1, LR-89 and Merlin all use kerosene and liquid oxygen as propellants, but the proportions of kerosene and liquid oxygen can vary considerably; the RD-107/108 run on kerosene, liquid oxygen and HTP but they use slightly different propellant mixes even though they're almost identical. Make sure you've got the right mix for your specific engine or you'll be carrying fuel (or oxidiser) that your engine can't use, adding to the "dry" mass since it isn't burnt and so reducing delta-V.

It’s a bug in stock KSP 1.10, I found it yesterday as well. 1.10.1 will probably be out in the next few days to fix it.

I took your plane and made some modifications- sorting out the control surfaces was the first priority, then changing the fuselage from a procedural tank to a modular one, then a few other fixes, a few test flights and finally a dubious paint job, to make this:

It uses the same wing parts and the same tech levels as the original, but when I tested it I managed to break 75km twice in the same flight. There's a bit of pitch instability at extremely high altitudes which RCS may fix, some further tweaks may still be needed but it works well enough for me.
Link to craft file: https://www.dropbox.com/s/kddgjacgs6xpljn/X-3M1.craft?dl=0
AG1 toggles engines, 2 lowers flaps and 3 raises them, 0 deploys the drogue chute and abort (backspace) controls the wingtip airbrakes.
 
And here's the design I made in my own RP-1 career recently:


I used an all-moving tail and a canard design which made it easier to balance the CoL and CoM, added split airbrakes in the awkward gap on the inside of the trailing edge of the wings, and most importantly tiny wheels on the wingtips so that if it landed badly and started falling over to one side it wouldn't destroy the plane (proven successfully on several occasions!). I didn't need RCS on it at all, plus with upgraded and stretched tanks and better engines it could use the X-15 cockpit and go to space.

Update to the latest version of Scatterer and the problem should be solved.

Sounds like you’ve got a corrupted KSP. If you got KSP through Steam, right click KSP in your Steam library > properties > local files > verify integrity of game files, which might solve the problem; if not, copy your save games from KSP/saves/<save name> to your desktop, then completely uninstall and reinstall KSP.
If that still doesn’t fix it, put the log files on a file sharing site and post links here. To find the logs, use this guide:
 

That’s a scatterer bug, try going back to scatterer v0.0723 as it doesn’t seem to happen with that one.

There are a few tricks that can increase your delta-V:
Simplify, then add lightness. Do you really need that part? If not, get rid of it and save some weight. Is it really practical to do such a complex mission right now, or can you get away with a simple orbit of Gateway with the occasional coincidental flyby of a moon when the orbits align? Can you get a gravity-assisted capture or aerobrake when you arrive? Try to find an encounter with the biggest moon you can so that its gravity will slow you down relative to Gateway itself and so will help you brake into orbit. The alternative is going for a really low periapsis and using Gateway’s atmosphere to aerobrake, but this is a high risk strategy as you could a) burn up, b) overdo it and fall into the planet or c) get wrecked by radiation, assuming Beyond Home has magnetosphere configs for Kerbalism and you’re using the radiation system. Orbital assembly will allow you to build something larger and heavier than your biggest launch rocket can handle in one flight. You can also launch partly fuelled tanks and then send up a tanker to fill them up later. Trying to cut the corners on transfers doesn’t work very well or very often. Stick to the proper transfer windows and you’ll save a lot of delta-V which means you can build a smaller, lighter mission.
Doing long voyages with Kerbalism is hard, but still feasible- here’s a ship I made to attempt a Grand Tour of the stock system, landing on every planet and moon (except Jool, obviously) in one trip:

It was huge, slow, laggy, weighed thousands of tons once complete, it didn’t even make it to Moho and I had to skip the Mun and Minmus on the way home too, but it got everywhere else and had decades of supplies for its crew of two. It’s all stock parts too, with the exception of the life support bits that Kerbalism itself provides.
There’s no need to build something quite so gigantic for a simple interplanetary mission, but you do need to keep an eye on the life support and also on the crew stress as stressed-out Kerbals have a tendency to accidentally dump food/water/oxygen overboard. Keep the crew happy with a spacious, fully pressurised ship and tick enough of the boxes to avoid stress buildup and you can run missions that last for years- add in the active radiation shield and radiation detox unit that you unlock late in the tech tree and you can run missions that last decades, just as long as you pack enough supplies.

KSP might run, but you’ll most likely need to turn the graphics settings right down, avoid nearly all mods and be prepared for the frame rate to tank if you happen to look at the ground. Try to avoid high part counts, turn physics delta-time up as high as you can to make the game run closer to real time and whatever you do don’t crash!
(The frame rate thing happened to me when my GPU died, despite 32GB of RAM the game slowed dramatically when I looked down, just because it was using the built-in graphics thingy to render instead of a dedicated GPU.)
 

The tutorials are old and outdated; the game has been updated several times since then and the rocket in the first launch tutorial is now an absolute deathtrap as the parachutes will never open in time before you crash into the ground. Try reducing the amount of solid fuel in the booster?

Check your keybinds (main menu > settings > controls > editor(?)), I believe it's the same key you'd use to toggle angle snap in the editor which is X by default.

Right…
First of all, why are you using stock parts in RSS? Unless you’re using SMURFF at full power to make them more realistically balanced, you’re going to have a really bad time of it. Stock parts are woefully underpowered compared to reality- fuel tanks have ridiculously high dry masses, engines have terrible thrust to weight ratios and so on- so I strongly recommend you either use SMURFF to rebalance those parts, or look into Realism Overhaul instead.
Secondly, the wing positions are wrong. Take the fins off the tail and put them near the nose as canards instead, then shift the main wings back a bit. Right now those elevons on your main wings are going to provide zero pitch authority as they’re right on top of the wheels plus the fins further back will cancel out their pitch effects, while the fins at the back don’t have much leverage to lift the nose off the runway; by swapping to canards on the nose you increase the pitch leverage considerably, pull the nose up (generating more lift) rather than pushing the tail down (generating less) and if you shift the main wings back those elevons can come into play too for extra pitch control, not to mention the fact that your lift will be more balanced relative to the centre of mass.
And thirdly, the main landing gear is a bit too far back. Move it forwards a bit and you might find pulling the nose up on three runway much easier.

Try using this guide to find all the log files: 
The logs will probably say what’s going on, but some more information from you might help such as:
KSP version; PC specs (processor, RAM and GPU are the most relevant but OS and hard drive may also help); If you have any mods installed, the names and versions if possible; Does the loading screen that never loads to the main menu play the main menu music?  
 

You’re doing it incorrectly- deployable science parts need to be deployed, not simply dropped.
Move the deployed science part into the Kerbal’s personal inventory. Right click the Kerbal, find the part in their inventory and click the little down-arrow-with-circle icon in the bottom right of that item to deploy it. Place the deployed science part with space bar. When deploying deployed science experiments, get a scientist to do it as this greatly increases the speed at which they generate their data; likewise, get engineers to deploy deployed power systems (solar panels and RTGs) as they will generate more power that way; in both cases higher level Kerbals boost the bonuses.  

Whoops, missed that 

Try pressing the # button on the top right of the part information window? That’s usually what does it.

Try pressing the # button on the top right of the part information window? That’s usually what does it.

Try pressing the # button on the top right of the part information window? That’s usually what does it.