My suggestion isn't so much about the program itself, but more how it could be distributed. This will likely be a very unpopular opinion, but honestly I feel like it would be better in the long run. Okay here goes:
I think there should be two different versions of SpaceEngine. One free, and one paid. The paid one is exactly as it is now, plus maybe a few new features. The free one has everything that the majority of users ever use - but all of the "sciency", less-known features would be saved for the pro version. The free version would fill the needs of most people in the community, while the Pro version would offer extra features to people willing to pay. It wouldn't need to be expensive or anything, maybe $15 or so.
Why? Well I was reading some past conversations here, and SpaceEngineer mentioned that the money from donations wasn't enough to both make a living and
hire artists or other people to work on the program. I think that in the end, this would not only benefit SpaceEnineer, but also the program and the community as a whole, by allowing him to spend more time on it and maybe hire additional people to work on it. Personally I think it'd be worth the trade off.
Some of the features that could be saved for just the pro version:
- The more advanced planetary info that most people don't understand or read anyway (Roche limit for satellites, Influence sphere radius, Argument of Pericenter, etc.)
- Spacecraft (Once they're fully completed it'd make sense for it to be in the free version, but currently they seem out of place in whats otherwise just a realistic simulator)
- Video recordings could still be present but without all the advanced controls they currently do - I don't think many people understand what all those do anyway
- Exporting planets/systems
- Advanced display options (Projection options, for example)
Anyway, just an idea. Hope people understand why I'm suggesting this, I don't just want people to have to pay for something, I do think it would be beneficial.