Opponent was pfr15//co50//3Bet--33.
Have I missplayed it on the flop or anywhere else?

Turn call is really bad. You have almost no equity

You didn't 3bet, in fact, before opening this thread I started thinking about situation where there is a limper and a 3better PF, it's impossible.

Cbet flop.
Check that turn.
Shove that river.

He didn't call turn.

check turn

I wasn't sure how this preflop line is called.
But it's limp raise i think.

Check turn and fold to a bet?
This tiny bets on the flop - I am unsure if A.) ist a blocker for a draw or B.) ist the nuts trying to get me make a huge raise.

How can I figure that out?

definitely cbet flop

The line is called OOP raise, or BB raise, to raise from the BB the other player must have limped, otherwise he would have raised and the line would be OOP 3bet . A 3bet is a reraise, so it would be a 3bet if he raised and you reraised, or if he reraised your BB raise.

Obviously, calling is bad, you have nothing.
A) a blocker bet is done OOP,
B) He definitely doesn't have sets, he would have raised preflop, maybe 22. 29 9q and q2 are possible, but not likely considering his wide range.

You will usually ask yourself if villain's bet is a value bet or a bluff bet, but when you have nothing and the board connects with a lot of his range, you shouldn't consider bluffing.

Check-Reraise shoving turn is not a bad idea if you have a tight image.

Your line's a bit fancy. Keep it simple by cbetting and checking the turn.