i think we should bet our range advantage OTF. small c-bet sizing seems fine.
don't think we should fold for 2/3rd pot with this hand. we're pretty under repped. i also don't think we should ever raise this exact hand here. i'd call.
You have the 4th nut low, and maybe the 10th best high (I'm not going to bother counting all the hands).
You can't stand a raise of any sort. Players aren't folding 23, and I've played with too many who won't fold a 34 with a 4 high flush here either.
If the opponent is observant, and sees you betting very thin spots (which this is, IMHO), he'll just lay in wait with strong hands and let you hang yourself.
I'd be happy checking it down.
But then again, I play with a bunch of sandbaggers!