[PvK]

I've only just started looking at modding, but I think I know the answers to much of what you've asked:

1. You can specify the year length of the missions to be huge in a mod. I'm not sure what the limit is.

2. Someone's already made such a mod, though it needs to get posted someplace without a monthly download limit - see the Battle Coliseum mod on another thread here.

3. I don't know that there's a way to do that in the simulator. You could probably make a mod where there is just one system to go to, which has whatever you want in it, though.

4. I don't know how one would do that, except you might be able to mod a game to start with whatever you had in your last game.

PvK