[PvK]

Most of the "good or bad" questions are simply matters of personal preference. That being the case, I think things that are different from the unmodded game are interesting, and thus usually "good" since they would offer a change.

1. No
2. No.
3. In general yes. As SJ said, max levels remove research from the game. However, not necessarily. If the game is meant to represent action on a scale where no major developments would emerge through research to affect the conflict, then that's ok. Also, it is one (though not the only) way to remove the issue with the unmodded game where more colonies means more ability to research, which always seemed at least slightly wrong to me.
4. Sounds good/interesting.
5. Sounds good/interesting, though as SJ said, it should be considered a major effect for balance.
6. Not really. You could of course have a ship that could destroy the planet and rebuild it, which would give you a random atmosphere change.
7. Sounds good/interesting.
8. Sounds good/interesting.
9. One.
10. Good.

PvK