100 Poker Hands

The villain is tight. Nearing 50 hands he has VP 16% and PF 13% of hands. The second villian who calls the early raise has VP 26% and we haven't yet seen him 3 bet a hand. It only costs another 2 big blinds to see the flop and the hero closes the pre-flop action. When the flop comes with an ace the hero must be a big under dog against this range. Did he play this hand right?

Sometimes you feel its worth defending your small blind, sometimes you don't. 3 betting with a pair of 5s when the big blind is still in the game can be a risk. But sometimes the flop is good to you. Of course sometimes you might think you could have made a bit more money.

What sort of hand raises an under the gun raise in online microstakes poker?  How far will they push their hand?  How would you play this one?