hero has $500
everyone else has me covered

a loose player raises to $20
i call with ad-qd
a solid player in late positon calls. he has only shown down quality hands
the big blind calls

As kh 4s is the flop

bb checks
preflop raiser c bets $60 ( he cbets @ least 75% of the time)
i consider raising, but i'm a bit leery of the solid player behind me.
solid player smooth calls.
the bb check raises all in immediatetly for $800. he has played a lot of hands, but never check raised, and never went all in.
preflop raiser folds
there's about $750 in the pot that hero can win for a $420 call.
hero?

I think this is a fold, considering the bets and calls before this guy it's not ridiculous for him to think someone is on a draw. I think the lower parts of his range if he's reasonable is combo spade draw, Kxss, Q10/J10ss, then stuff that crushes you - set/2pair. The caller behind you likely has a draw or a hand like AQ/AJ as well.

Instafold

This is a safe board with reasonable expectation that someone will bet behind it from BB's point of view. There are 0 draws you could put the villain on. The only thing you're beating is a middle pair bluff and an overplayed A-J/ A-10

instafold, this is a hand you need to get away from.

OK, fold. Seriously. This is always a set or AK. You have few outs here.

what if i changed the image of the checkraiser to a loose maniac?

Then I change my opinion to A4 and still fold.

Get out fast. I mean real fast, and be glad you didn't raise. I hate AQ on a board like this. Especially with no redraws.

i folded as did everyone else. the solid player behind me had A J. the guy that went all in showed one card, an Ace. he then went on to bluff at about 30% of the pots and play top pair the same way.

i never like AQ in a spot like that, but after watching him donk it up for a few hours, i wonder whether i should have called.

If you're not folding the best hand occasionally, you're calling too much anyway. He was probably just setting up a stupid table image. I'm willing to say he had A4 more than 80% of the time.