This is a spot I find myself in often and don't know how to play it. Happens at loose tables.

I raise AK from EP. I get a bunch of callers (4 or 5) because this is 1/2.

Flop comes Ac9d3d.
I bet like 75% of the pot and get 1 or 2 callers.

Turn comes 7d.
Now what? Do I bet again? Do I check call? Do I check fold and let myself get blown off my hand? I hate this spot. For the sake of discussion I hold no diamonds.

It depends

This. This is way too general for a one-size-fits-all answer.

How much did you raise preflop? Why did you choose that sizing? What are your reads on the players that called your raise? What are their stack sizes? What is your stack size? What's the size of the pot heading to the stacks? What are the positions of the players who called your flop bet? What are your reads on them? What are their stack sizes? What's the size of the pot heading to the turn?

Depending on the answers to these questions, you might sometimes bet an amount to put both your opponent(s) all-in, you might bet a certain amount with the intention of folding to a raise, you might bet a certain amount with the intention of calling a raise, you might check/call, you might check/fold, etc. I'd say that the majority of the time I'm bet/folding in a spot like this, but again, it's so situation dependent that bet/folding could be terrible in your specific spot.

This is too general a question to answer. Even the number of callers on the flop makes a difference to the results which you apparently didn't feel was important.

Start over, give some reads on the specific villains and you'll get better answers.

Locked.