Strong HU move, or just spewing chips??

I'm trying to figure out heads-up play in a full ring game, particularly when I'm OOP. Here's a 2/4 hand from PokerRoom. Comments on the check-raise as well as PF is appreciated. I just called the raise to keep the BB in, as I figure I'm OOP anyways, so why not pad the pot w/ a premium hand. Is this good? Or best to just try to get it HU right off the bat (he didn't call, so it doesn't matter w/ the action).

Hero [ AH,KH ]

ANTES/BLINDS
Hero posts blind ($1), BB posts blind ($2).

PRE-FLOP
2 folds, Villain bets $4, 2 folds, Hero calls $3, BB folds.

FLOP [board cards 7H,5S,9C ]
Hero checks, Villain bets $2, wrf1979 calls $2.

TURN [board cards 7H,5S,9C,9D ]
Hero checks, Vaillain bets $4, Hero bets $8, Vaillain folds.

I had no read on villain, as he was new to the table. I figured there was a good chance I was at worst chopping with him. When the 9 paired, I figured it was a good chance to bluff at it, although I may have been ahead anyways. On a side note, one thing that made me think about slowing down a bit was that he when it was his turn PF, he seemed to have the RAISE option checked, as it was instant. Do you all consider this a strong tell, or pretty random? I know it could be either Raise to $4 (or w/e 2xBB is), or Raise Any, the latter which would obviously be a much stronger hand on average.
Anyways, on the line I took, I'd like comments on what I should do if he had done something other than fold. I figured I would fold to a 3-bet, or check/fold the river if he called then bet the river. Would a call-down be appropriate against an unknown in this situation?? Thx in advance.

[jt1]

The turn play is excellent. What if he had called?

Preflop, raise! Lead the flop and don't slow down until the river.

You raise 'cause though your hand plays well multi-way, it's better HU then it is against 2 others. And because you have the best hand

[sean c]

I would three bet pre flop

[paperboyNC]

Please use the suit icons so that the hand is easier to read.

A) 3bet pre flop


I play AK unimproved post-flop the way you did a lot. I love the turn check-raise.

[TheHammer24]

Your logic is very flawed about why you didn't three bet preflop. I would recommend reading some more. However, the turn check raise freaking sweet. nh.