I'm up for first three options.
I would like to be able to fly through the space in either Spore's RTS-ish type, click to fly to, or like in Star Trek Online, controlling your ship normally with WASD and few other buttons.
For solar systems and planets, I'd like to be able to beam down to planets, whether in one of those environmental suits for hazardous planets or not for those planets who aren't. I'd prefer it to be viewed from a 3rd person camera, you know, like a RPG game, but 1st person camera would be good too.
And for your 3rd option, regarding non-violent options with new races, I'm always up for that. Diplomacy, however, is a very broad area to work on, because you can think of thousands of way to help people without combat. Share research or help them develop their own, save them from a planetary disaster, help them fight some kind of plague/sickness, etc.
I'll admit, this sounds more like a RPG game, but I guess this kind of game would do.