Your post seems a bit confusing, usually at 200/400 and on the bubble you are pushing or folding.

Its also very dependant on how big of a chipleader you are, and how small the other stacks are.

1)KK I would minraise on the button, if called I would probably go allin (pushing or calling) any flop without an Ace.

2)Depends on too many factors
3)Depends on the size of the stacks still to act. If I have a huge lead I'm probably bully pushing into them. Hell, even if THEY have ME covered I'd still push from SB and possibly the button.
4)If there is a raise that isnt allin at 200/400 then the player probably doesnt understand how to play, or is trapping with a monster. In either case, Im not playing suited connectors against a raise.