Would call first hand. Plays well and hits middling boards nicely. This deep I'd most likely ship something like A9+, 22-77 (88-JJ if i think he will call wide), 3bet some broadways (but if he shoves over I think you have to call those... TJ+, but again, factor in his fold to 3bet ).About second hand, I probably wouldn't go into excessive 3bet wars this early. You are at full stack and going crazy over 70 chips pot. I would pay attention to my 3betting frequency because if its too high I would often expect not to get credit for 3bet, and induce 4bets/shoves from a villain. Folding Q6 also, plays really poorly on flop.

I think the first hand you should fold.  Its a hand that flops well, but at 20bb effective stacks against a 2.5x from an opponent who isn't raising terribly wide (I haven't checked stove for 48% range), I don't think its going to be better expectation than folding.  The second hand is opponent dependant.  I *do* think its a good hand to 3 bet bluff with, but if you have been 3 betting a lot recently, you have to consider the natural game flow.  You can't force the issue.  Its all about making the best play at the time, and given you have 3 bet more than enough it is less likely he is going to respect another 3 bet.  Or even worse, he might just get frustrated and start playing back with weak holdings, to which you have to fold.  I think the *best* play given the information you have given us, would be to call.  If he was only raising 50%ish pre, I would fold.  I don't have my stats to hand, but I would be surprised if calling Q6 is worse than folding to a 2.5x this deep.  Of course another factor is how strong a player you are out of position post flop.  Folding is probably very close in EV to calling if you consider yourself to be a weak post flop player.