Check-raised turn and called. River advice please...

[Haplo]

No info on villain.

Full Tilt No-Limit Hold'em, $0.50 BB (7 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP2 ($43.20)
CO ($217.10)
Button ($101.50)
Hero ($50.25)
BB ($49.55)
UTG ($15.55)
MP1 ($49)

Preflop: Hero is SB with K, J.
[color=#666666]1 fold</font>, MP1 calls $0.50, [color=#666666]3 folds</font>, Hero completes, BB checks.

Flop: ($1.50) 6, K, 6 [color=#0000FF](3 players)</font>
[color=#CC3333]Hero bets $1</font>, BB folds, MP1 calls $1.

Turn: ($3.50) 3 [color=#0000FF](2 players)</font>
Hero checks, [color=#CC3333]MP1 bets $2.5</font>, [color=#CC3333]Hero raises to $6</font>, MP1 calls $3.50.

River: ($15.50) A [color=#0000FF](2 players)</font>
[color=#CC3333] Hero ??????

Two questions: 1) On the turn with a scare card oop, what do most of you do?
2) Given the way this hand was played, what would you do on the river here?

I checkraised the turn because I didn't know if he was making a play on me since I had checked. I figured I could fold a king and I wanted to know where I stood. But in retrospect I don't think this is usually the best play (perhaps sometimes to vary things up but usually not). A cheaper way of seeing where I was would've been just betting out say 2 bucks on the turn and folding to a rz if he would've raised. That way I might save 4 bucks if he has the flush. If he doesn't rz then I reevaluate on the turn.
What do you think?
Thanks