I think KQ is my "tough decision" line.

He didn't miss his draw, so I'm not sure what point you're making here? He doesn't bet a missed river, which is what I consider to be bluffing a missed draw.

He was semibluffing, and then checked a bink river because he was afraid of being raised by a flush. He should b/f river, but he plans to c/c obviously.

If he bets here on a brick river, then yes, your point is valid and hands like this become more valuable to us. But we need to have some reason to think he does, and a l/c after two folds is not nearly enough info.