Hand 1 - Push...Even if your behind, you have outs with a Q for a straight.

Hand 2 - Tough spot b/c you say these are the 2 loosest players at the table. If you have seen him do this before with a flush draw, maybe you can call, but I'm inclined to lay it down. Just too many hands that beat our 1 pair.
Re-buy and wait for a better spot.

Hand 3 - clear fold to me. Tight player calls our big raise on the flop and then pushes on a blank turn...I think our KK is no good.