Pending Twilight Imperium 3 questions

[Derrick Heyoka]

1. Can action cards be traded?  If so when?
 1b. How about other things like trade goods?  Same rules apply?

2. Joc noticed there is at least a small (?) penalty for losing your homeworld(s), you can't get VPs for secret or public objectives (as I recall?)  Is that it?  We assumed the Imperium Strat card was still fine though, we should prolly make sure.

3. Is the ONLY way to stop someone from winning to remove them from the game entirely (like last night).  No other way to hold them off?  Or does that even work at all?  If so, is every single ship really necessary or will just leaving them planetless be enough?

4. Does starport production capacity limit a starport for the entire turn or just per activation?  I.E. if you manage to deactivate its hex somehow later (w/ an action card or Warfare) can you produce more crap even if you max'd it out earlier?