re: Poker & Bubble play vs aggressive players
Position is key, too. Obviously if the maniac is to your left, all your steal attempts have to go through him, and what Egon said is pretty much a perfect description of the way you have to play in this scenario.
If the maniac is a seat or two to your right, you're actually in a quite ideal situation. While you may not try to steal with A3s if you had to get past a maniac sitting to your left, if the maniac has already folded, you're in LP (or in any position on some occasions, depending on the table) and the blinds (or players behind you) are tight, you're free to go for it.
Essentially, practice basic "Steal from the tight shortstacks who are trying to just make the money, stay away from the loose bigstacks" bubble strategy. Of course, in tournaments your seating is purely down to luck, so if you do have the loose bigstack to your left there's not a lot you can do about it - just remember these situations even out in the long run.