P4's,

The main problem I see in your thought process with regards to hand valuation has to do with the fact that the flop was 4 way. Were this a heads up or even 3 way, the scenario becomes much different and your hand becomes quite a bit stronger. But in a 4 way pot, there's no way you get more than one street of value with this holding from anything you're ahead of at 1/2. 1/2 plays so nitty postflop, no one will c/c a fd twice unless they are super fish, and 80% of players will fold AT to one bet. Also, anyone with a set is dumb enough to be slowplaying. You are much better off checking back the turn and bluff catching the river than you are to bet the turn and then guess whether or not to call or fold to a shove.

edit: also, don't get so defensive.