Ultimate Bet No-Limit Hold'em, $.50 BB (9 handed)

Hero ($84.35)
CO ($29.40)
Button ($48.40)
SB ($140)
BB ($36.75)
UTG ($49.25)
UTG+1 ($32.85)
MP1 ($41.65)
MP2 ($37.90)

Preflop: Hero is MP3 with , .
1 fold, UTG+1 calls $0.50, MP1 calls $0.50, MP2 raises to $1.5, Hero raises to $5, 2 folds, SB calls $4.75, 1 fold, UTG+1 folds, MP1 folds, MP2 calls $3.50.

Flop: ($16.50) , , (3 players)
SB checks, MP2 checks, Hero bets $12, SB raises to $24, MP2 folds, Hero folds.

Final Pot: $52.50

Results in white below:
No showdown. SB wins $52.50.

1. Was my raise high enough? It was over 3x the initial raise and only SB could call (cold call re-raise OOP!!) with odds to set me.
2. 3/4 bet on flop too weak? I usually bet somewhere between 80-100% pot.
3. Whats villain got? I'm figuring the only possible holding i'm ahead of is AJ. I wasn't prepared to risk my stack to find out if he was playing TT or 99 (possible) but I think more likely AA, KK or JJ 55 44. AdKd possible but he usually pushes his draws.
4. His stats were VP 33% PFR 13% AF 5.6 only first session i've come across him but was winning big: up 40PTBB/100 over 400 hands

Unless hes an idiot, he has AA / KK. I would need a good read not to fold this.

Unless he's a maniac or muppet you're beat. Just as you say, he should have AA-JJ which all beat you, or AKd which is actually ahead too. Most likely is JJ I think, judging by the check/mini-raise.