Hand from Viejas

[mimicme]

Quoted from my friend's blog

i'm playing at viejas at 1/3 nl. i am in the big blind with K7d. UTG is a maniac and, as he does every round, puts in a live straddle. 3 calls before me, i call. flop is Ad 3d 7h. i check, hoping to put in a check-raise. UTG dutifully bets 15 dollars and everyone folds. i raise to 35 and he instantly calls. the turn is the Kc.

1) should i check or lead out?
2) having checked, UTG grabs a stack of chips and splashes
them into the pot. he bet 55. what's my play?
3) would you lead the flop ? 3 bet? call?