Well, if the "stupidities" are made for other players, there are opportunities to usually doble up your stack.
1. Play aggressively at the start: In position with premium hands, no problem to call - push all in against "aggressive fish".
2. Flop, flop, flop. I interpreter in another way, no a player who go one and another and another flop, however, a multi-limp with position and premium, squezze time.
3 - 4. Not fold monster hands - pay preflop small pairs. Again, in position and less than 5% of my stack, call with small pair and only wait for the set or be the gutshot of a straigth draw. And viceversa.
5. Show preflop hand. Never, never, never. For general rule, my pokerstars
setup is never show my hand, only when is mandatory.
And these "tips" if you start a tournament since begin. I usually start at 25-50, 50 - 100 level, to avoid all the situations that you describe.