Do You Ever Worry About a Better Two-Card Flush?

Early in a $15 tournament. I've seen nothing but loose, straight forward play so far- people limping, checking, calling with marginal hands or draws and betting or raising strong made hands. I may appear a bit aggressive, as I've played a few hands aggressively and won without a showdown. The only hand I've showndown is AK that made top pair on the flop and top two on the turn.

Everyone else in this hand has ~1200, their starting chips. I have ~2800, blinds are 10/20. Three limpers, I limp T[img]/images/graemlins/diamond.gif[/img]8[img]/images/graemlins/diamond.gif[/img] in the SB, BB checks.

T100 in pot, flop is 6[img]/images/graemlins/spade.gif[/img]9[img]/images/graemlins/diamond.gif[/img]2[img]/images/graemlins/diamond.gif[/img] I bet 50, BB folds, all the limpers call. I am happy building a pot right now, and would love to see a raise after I get a few calls- I want as many people in this hand as possible. I don't put it past anyone to be calling with just overcards, which means at least two of their 'outs' are dirty. Same for anyone playing a straight draw.

T300 in pot, turn is 3[img]/images/graemlins/spade.gif[/img]. I bet 200, once again get three callers. At this point, I would expect overcards to fold. I start to think it is very likely someone else has a flush draw, though of course a worse one than mine is possible.

T1100 in pot, river is J[img]/images/graemlins/diamond.gif[/img]. What's my play here? The others all have ~900 left, I have ~2500. I believe someone else has a flush that may or may not be better than mine. A push will probably be called only by another flush.

Just so we're clear, I'm not considering folding, I'm just wondering how I can get the most money in the pot from hands I'm ahead of and whether I should be concerned about limiting my losses against a better flush. Should I weak lead and call a raise (or push over a raise)? Check-call? Check-raise all-in? Push?