I agree that we should focus on utilization, payloads, and stuff to do once you get somewhere. Start with your last question about KSP2 - well, like you said it's still in the future and we don't know what it will be like. But judging from what we DO know, things like surface bases, rovers, etc will be much more fleshed out in KSP2. Once we've ported the existing parts over, I'm definitely interested in expanding based on lunar/martian surface base proposals. That's a long way off however, and I'm holding off until we have more info about how those systems work, and how to create new 'parts' for them. Similarly, rovers in KSP 1 suuuuuuck to make parts for, so I'm holding off on those for now - but we have a bunch of different rover designs we can attempt in KSP2.
So, broadly speaking, I think our (my) content for the rest of KSP1 will follow these lines:
Things that are suitable for KSP1 - landers, small surface habs, things like that. Nothing that needs new gameplay systems to work (as compared to full bases, which I'd want to try and implement via KSP2's colony system maybe?). So stuff that only adds relatively basic missions, like the I-class CSMs with the KH7 camera, those would be good for KSP1.
Focus on having the groundwork laid for KSP2 - things like interplanetary transfer vehicles, orbital tugs, upgraded LMs that could serve as scouting/survey missions. I could see us taking elements from IPP but I'm not really interested in doing the entire thing. You might think of that stuff as like... IPP, but in an Apollo/Saturn centric timeline. My point is, we'd like to flesh out the parts you'd use to get to the point of developing early permanent lunar/martian bases. These are things that ARE doable in KSP1.
Focus on CSM/LM follow-on stuff - I'd like to keep expanding and developing these part sets, rather than adding new families. So if something is CSM but with X, cool. Something like the Advanced Crew Vehicle from ETS, which shares little to nothing with the CSM and would essentially be another purpose built part family, is kind of a non-starter for me. I will say, I have very little CSM stuff left to make, based on the documents I have. It was relatively static, compared to the proposals for the Saturns and LM.
Making sure that models/assets are up to snuff. Things like the current Atlas parts need a large pass and wouldn't be worth porting as-is. Getting those out of the way will be a big help.
As of right now, we don't have much info on what will be required for porting to KSP2. There's going to be a lot of stuff missing - certainly no B9PS at release - so we'll have to play things by ear. It probably won't be for like, a year after KSP2 comes out (at minimum) before BDB, as it exists now, is fully ported. At least I'll have a head start on being the definitive USA part mod
Responding to these more specifically:
1), 2), 3) LM Taxi, Shelter, Truck, and Lab are priorities for the next update. I definitely want to put them in.
4) See above, I'd like to hold off on making rovers until KSP2, since the implementation of wheels hopefully won't be... badS but without the bad if you know what I mean. I really hope you can have stupidly flexible suspension and proper traction like in the trailer.
5) I'm actually not sure what you mean?
6) Yes, we're looking into it. I know Zorg has plans, and the LM-Lab might also include a 'short' descent module that more just acts as an experiment mounting truss.
7) Some amount of LASS/ALSS will probably make it in, but again, I might hold off in hopes that I can make a much more interesting and fleshed out experience in KSP2.
8) So, I always was interested in doing those? But the problem you run into - and this goes for a lot of early proposal type stuff - they're just not that detailed. if you took the 1962 model and "finished" designing it, it wouldn't look the same. That's my hang up with that sort of work, doing the early conceptual stuff like that. The Alternate Apollo LM is great, but you can see what I mean - it's not nearly as detailed as our LM. I'm not knocking mcdouble, I'm saying he put in basically all the detail that was available on that OG LM.
9) We were discussing this in the dev chat the other day. It's a possibility; it got pretty far along and there's some good documentation.
Finishing off by listing out some stuff I know we're seriously looking into:
As stated, the AAP LM variants.
Zorg's looking to expand the nuclear engine stable, maybe including a BDB NERVA (finally!)
"Orbital Launch" concepts - basically, docking a payload and 1-3 S-IVBs in orbit and then doing a departure burn. This would include aft-to-nose docking for S-IVBs.
Some way of controlling or eliminating boiloff, probably at the cost of EC.
Zorg has a number of Skylab-adjacent things to look into, like EOSS and I can't remember what else.
Revamp of the cylindrical Big G service module.
I was thinking about making something like the Orbiting Primate Spacecraft, but re-imagining it as maybe like, a long term Mystery Goo research facility? (I'm don't like actually depicting animals in KSP, it feels like it darkens the tone a bit too much. The Goo, with it's gregarious personality and possible... alive-ness, is usually used as a substitute, since it doesn't seem to mind)