So i'm looking for specific mods/plugins...

[Zutha]

That:

1. adds spaceship details like mass per stage, total mass.

2. Calculates delta V per stage

3. Has angles for interplanetary missions

4. (optional) allows switching between craft without going to station.

and most importantly:

does not effect any parts or saved games so it's kept stock.

any ideas?

[42undead2]

You can already switch crafts without going to station. Use the [] buttons. Also, I think Kerbal Engineer Redux may be what you're looking for. I haven't tried it yet, so it may not fit your criterias.

[Zutha]

Thanks looking at it now. Says something about adding a part though, but hopefully can do to get details and then remove before flight

[TaranisElsu]

You can use the Build Engineer part in the Kerbal Engineer, as it is intended to be used only in the editor and then removed. It does not give you anything during flight (the Flight Engineer part does both). That will give you 1 and 2.

For phase angles, I recommend Protractor (http://kerbalspaceprogram.com/protractor-for-ksp-0-18/) but it sounds like you want to keep your flights stock and just want help planning. See if this helps: "Interactive illustrated interplanetary guide and calculator for KSP" (http://ksp.olex.biz/)

As 42undead2 said, you can switch between close vessels by using the [] keys -- close being defined as within 2.4 km. For others, you can click on them in the map view and select Switch To. There is also the Haystack mod (http://kerbalspaceprogram.com/haystack/), which makes it easier.

[brians200]

One of tools that the Lazor mod has is showing you the angles and when to leave for transfer. It has a ton of other tools as well