What would you do?#106 - Slow played KK

I've been playing around with a few different styles, with my main focus being deceptive play. I've been check / raising a lot more flops, trying to slow play monster PF hands, etc. As a result, I've been getting into a few more interesting situations, where, out of position, I'm having tough decisions:

Full Tilt Poker $0.25/$0.50 No Limit Hold'em - 9 players
The Official DeucesCracked.com Hand History Converter

BB: $72.55
Hero (UTG): $69.90
UTG+1: $51.25
UTG+2: $31.05
MP1: $30.10
MP2: $89.95 - 9/4/ 11% steal / 0% 3bet / 1.5 aggression factor over 157 hands
CO: $126.45
BTN: $50.00
SB: $25.00

Pre Flop: ($0.75) Hero is UTG with Ks Kd
Hero calls $0.50, 3 folds, MP2 calls $0.50, 1 fold, BTN calls $0.50, 1 fold, BB checks
Well, when I was looking ahead at the players in front of me, I saw a bunch of aggros that I figured would be raising.  I did not get what I wished for, as I now face a handful of limpers.

Flop: ($2.25) 7c Qs 2s (4 players)
BB checks, Hero bets $1.50, MP2 raises to $4.50, BTN folds, BB folds, Hero calls $3
No Ace, which is a good thing.  I think it may be a mistake to lead this flop; instead I should be going for a check / raise.  However, when I get raised, I have a tough decision... remember this is a 9/4 we're dealing with...  The one good thing about this hand is that I'm no longer monkey-in-the-middle; i.e. BB & BTN have folded so we're HU.

I decide to cautiously call the raise.

Turn: ($11.25) 5d (2 players)
Hero checks, MP2 bets $6, Hero calls $6
Check / call and hope for a cheap river...

River: ($23.25) 4c (2 players)
Hero checks, MP2 bets $12.50, Hero calls $12.50
And finally, a fairly "cheap" river.  Very dangerous... I know...

Final Pot: $48.25
Hero shows Ks Kd (a pair of Kings)
MP2 shows Qc Ah (a pair of Queens)
Hero wins $45.85
(Rake: $2.40)

So here's the What would you?  Given that you're determined to slow play KK, and you get limped on, what do you differently in the hand?  Are you raising at all?  Are you going to be nit / passive like me?

His flop raise shouted sets to me, but by the river bet, I felt a lot more comfortable that he did NOT want stacks in, and bet half pot, indicating a medium strength (i.e. TPTK) hand, which is where I probably failed to make the proper read and raise the river.  Oh well; I learn for next time.

Disagree?  Is this dangerous though?