i personally would've raised more pre flop so i could get a better feel of the range of hands he could be playing oop against me, but i understand you're trying out a new strategy. (hope that goes well for you btw)
i personally do think that in the long run with ak it does make sense to just flat call his bet, but i would've liked a 4-bet for a couple of reasons (let me know if i sound too farfetched). given the fact that he's steaming and wants to get the money in, the only combo draws you're afraid of in that spot are aj and a4 (j4 seems really far fetched to me unless he really is as spewy as you say) so it's quite credible for us to re-pop him here given how wide his range is.
with such a heavy flop for straight draws and flush draws, we can narrow down his range of hands if he does flat call the 4-bet and if he does bet the turn, given how strong the line we have taken, i think we can safely fold in position.
but then again thats my playing style and honestly i think there was nothing wrong at all with the way you played it, there are def better spots you could pick against him. the best thing in this spot you can hope for is for him to have kq or q10 or k10, that we could get out of the ugly turn by betting him out on the flop. and if he does shove, our 4-bet kinda puts us in a justified call anyway with only a small range of hands behind ahead of us (a4 aj j4 aa jj 44).
just my opinion :) like i said, totally justified folding his turn bet. i def won't go for a shove cos it just seems a little weak in the spot cos a flush would've just called i think and a full house def would've done so as well.
good fold i think! regardless of the good bluff scare card