Bottom set, lots of bets, slow down yet?

[meow_meow]

Seeing as villain limped preflop (and didn't reraise), I think you can all but rule out KK. Really, you are afraid of exactly one hand.
Set over set happens.
Set vs. 2-pair/TPGK happens more often.

I would cap the turn. I don't like the river K so much though, given that K2 and K3 are real possibilities. I think it's close between bet/call and check/call (assuming villain caps the turn).