Early Turbo Tournament Hand

Greetings!  

Seeking feedback on this hand please.  Villain UTG was new to the table.  Took some time before calling my preflop raise after his open limp.   On the flop, he tanked for ~20 seconds before making the call. 

My questions...

With  a stack size of 12 BBs, would this have been a good hand to shove over the  1 limp preflop?

I’m second guessing the size of my flop bet.  Would it have been better to go all in or check back rather than bet 1/3 pot?

When checked to on the turn, should I have shoved holding a gut shot and an Ace? At the time in the hand, I felt my stack size seemed too small relative to the size of the pot to have any fold equity at that point, so I checked back.  

When players limp UTG I typically put them on suited aces A9 and below, medium and small pocket pairs and suited connectors.  By the River, I felt he would have kept all of his suited diamond cards and pocket pairs, so he either had a busted diamond draw or a pocket pair.  Does this sound reasonable?    

I folded to his River All-In bet, but would it have been better to call?  I left myself with 4 BBs and was all-in a couple hands later and busted out of the tournament.

Thank you for your feedback!  I appreciate having the HIT as part of our Membership!

J