This.

Limp/call pre + donk here screams I HAS A KING! Especially if you have no balance in your game. How often do you see a donk bet bluff in LLSNL from a limp/caller?

Dominic wins the thread for what I would do on the flop - check/call.

I build up a stack by playing aggressively and then switch to a fit or fold strategy, which quickly becomes transparent and exploitable. The adjustment I have to make to that exploitation is not optimal. So I just wind up making less and less money over time.

With regard to balance, that's an excellent point and maybe it's the whole thing.

KQo is a very marginal opening hand for me UTG but I like playing small pp in early position and its the same exact thing, it doesn't take long to figure out the limp-call-donk line. I mix it up with JJ and TT, sometimes limp and sometimes open raise. However I think I need to open raise small pp more often, cuz I never limp QQ+ here.

If you want to win big with your big hands, (vs other than droolers), you have to be betting big with a wide range of hands overall. Thsi gives the balance and uncertainty to others thus they are confused as to whether you have the goods or not.

This confusion leads to profits. You start limping everything except your very large hands (safe/secure hands) then your game becomes transparent even to fish.

Work to "up your game" and get it working on a more aggro level, rather than "back off your game" and get it to a nitty safe secure gameplan which everyone knows cannot win large sums of money / hour.

Kq not the same as small pocket pairs. Small pockets make monsters that you can value bet a lot. With kq you rarely have a top notch hand.

I think you're worrying far too much about being exploited. It's a tough lesson I had to learn. Most of them are incapable of exploiting you so don't worry about it until it starts happening.

Trust me Villain's range is so wide here, he might even call u with A7o on that flop..This is 1/2 dont forget..

This is gold here. OP - start to think along these lines. Yes, it is ok to lead on the flop... when you have a good reason (passive call station opponent). Yes, it is sometimes better to check-call (when villain is aggro). Yes, sometimes it is correct to check-raise here (against a Villain who will always and only single-barrel). The point is, predict your opponents range and actions - you won't always be right, but working on a theory based on limited information is better than not working with a theory at all. At least you will have an exact plan for how to continue against the different paths the villain could take.

Also, in this hand. Bet-fold on the turn here. If called, bet-fold on a safe river again. I can't figure AK in this guys hands, so you have the one-pair "nuts". Any two-pair should raise you at some point.