[MarkGritter]

So, if you want to bet-3bet the second round, or bet the third round unimproved, the question in my mind is what else do you play that way? If you do it with just 7432 then you are potentially giving up valuable information.

You should be a little wary of putting more money into the pot when you are out of position. Your edge could be narrower than you think since your opponent has a drawing advantage, in addition to some ex-showdown equity from acting last. However, I tend to think that your read is good and you should be willing to gamble it up a bit here, at least occasionally.

2nd round: Bet/call is fine to drive out the rest of the players. Did you consider a check-raise, or figure that the 1-card draw might be too weak to bet unimproved? I think it is probably close between driving players out of the pot (8.5 small bets already is worth fighting over) and exploiting your equity edge. Your relative position is good.

3rd round: A bet might occasionally win the pot here, but check-call is certainly the correct default play. The pot is large enough that you are obligated to call a bet or raise; conversely this means your opponent pretty much has to call (or raise) instead of folding. There are 6.5 bets after he bets, so you are certainly getting odds to continue even if he only bets 875xx and better--- you'd have to be certain he has a 7 to fold!

4th round: He stood pat on the last draw, correct? If he did not, this is an automatic bet. Even if he did stand pat, it is worth bluffing with your worst pair; not necessarily every time, though. Given the third round action he could easily have a 9, T, or J instead of a made 8--- if you can get him to fold just 12% of the time then the bet is profitable. You also want to bluff often enough that he can't automatically fold whenever you come out firing with a legitimate hand.