Hand 1: I definitely agree with your fold to his check raise. I also agree with your continuation bet - which was consistent with your play on the other two hands as well. You needed to find out if one of the other guys had an Ace. If the villain didn't have an Ace, he made a great play by check-raising you. Also note that he may have a read on you and didn't believe you had an Ace.
Prior to the flop, I'm unclear whether you were the first in the pot and the two callers were the blinds. In that case $10 is too large of a preflop raise. That's a minor point because they obviously would have called smaller raises, too. If one or both of them limped in, your $10 raise makes more sense. It also helps define their range a little bit. What would really suck is if the villain had A5s, or something and was all set to fold to your raise until he got priced in with the other guy's call. But, since you described V2 as TAG, you can feel pretty confident he had an Ace.
Hand 2: Also unclear about the preflop action...if the others limped to you, I really liked your raise from the SB - try to take the pot down there. If that's the case, WTH is up with all of the limp, call a raise stuff at the table? You indicate that you didn't like the flop, but I think it's a good flop for you (depending on what X was - if it was an Ace or Face Card, I wouldn't like it so much). From there, your continuation bet was reasonable. Your opponent's call could indicate a draw or two over cards. If he had a 3, I think he raises you (I would have). Even though your turn bet put you all in, it was still a reasonable amount (1/2 the pot), pricing him out of most draws.
Hand 3: Same questions about the preflop action. Are there a lot of limpers that then call raises? Or does no one at that table respect a raise? Or do they simply not respect your raises - meaning you're playing too many hands.
Anyway, you're in a 6 way pot with a pair of 5s and an overpair on the board. Not exactly a dream scenario. Could any of the other 5 players be playing an 8 9 or 9 10? Definitely a possibility - all of the limping and calling of your raises is pricing a lot of hands into the pot.
The texture of this hand is a lot different than Hand #2, so I think you were better off checking and seeing the free card. I'm much more concerned that someone could have had a 9 in this hand than I am someone having a 3 in your other example. I'm more inclined to give this one up all together. Your pair of 5s is simply not very good in a 6 way pot.
Hope that helps...Thanks for posting the hands. It's good exercise to think through these things.