AK is is my most profitable hand.

It brings home more chips than AA (not per hand, but the fact that I get AK (suited or unsuited) 3 times as often as I get AA.

In EP you gotta raise, but not that much. You want to raise so that weaker aces and KQ is willing to give it a call. Raise 4xBB. You'll hit the flop about a third of the time, so you wanna build the pot and get 2 or 3 callers. Check the flop if you miss, and call if you have odds on overcards/gutshot draw and fold otherwise. Bet about 3/4 pot if you hit TPTK or better. If minraised on the flop I assume my hand is good. If flat called on flop and raised on turn, try to get a cheap showdown.

In late position, raise as much as you need to isolate. You'll get a feel of that as you play the game more. In my game, probably raise to 6BB or 7BB if there are limpers. Then use your post flop skillz... if you managed to isolate, cont bet about 80% if you miss. With 2 players, look at the flop and see. Free card is never bad either.

So in a nutshell: in EP, raise smallish and try to hit TPTK and hope u got some moron outkicked.
In LP, isolate and look to cont bet.
In the blinds, isolate and look to cont bet. A large raise here. You'd like to get the limpers to fold if possible.

Facing a raise, reraise the pot if in position. Fold to a pre-flop re-raise. Cont bet almost any flop hard and check/fold if called. If you hit TPTK you gotta assume your hand is good. Facing a raise in the blinds... I don't know. You can call if there's other players who have called the raise. If it's just you and the raiser, you can fold or you can reraise and cont bet OOP if you're feeling adventuorus.

I play 200NL. But the principle is the same

P.S. if you vary the size of your PFR it's not because of what hand you got (unless it's AA/KK). In MP you want to raise enough to get position and hopefully a limper will come along for the ride. In LP you want to raise enough to isolate. In EP, raise so you can get a few callers (including dominated hands). Doesn't matter whether it's with AK, AQ, KQ, JJ or whatever. Cont bets should be probably 3/4 pot to 4/5 pot. If you actually hit on a rainbow board you can occasionally go for a 1/2 pot bet.