What are the specific mechanics of Ground Combat?

[Suicide Junkie]

1) Multiplies, but yes.
2) Correct
3) Yes, and they are shared, just like on sat stacks. So one command troop can give everybody the bonus.
4) Not sure
5) I'm fairly certain it goes simultaneously, since I'm pretty sure I've managed to lose troops on the final, winning round.
6) Almost certainly
7) Yep
8) Yep... although happiness will drop rapidly, and rioting planets can't build.
9) Sounds about right, but don't forget to consider price as well, especially at low tech.