how would you play this hand vs a reasonable range?

tough to answer cause opponents have wildly differing views of how to play as the 3bet caller on A high boards. Need some reads on him and also how he views your 3bet tendencies from sb v button.

readless i probably pot/call for a few reasons.
-you have a 9 and the 5 is one of the unlikelier straight cards to have hit him.
-you can get some better hands to fold by betting like QQ87 JJ75 QJ85 that might check back and get to showdown. you wont fold out a hand like 765 but naked 2 pair without an ace you can
-he has hands that have many outs vs your hand that might not have outs vs your range, i.e. QJT8
-i think you need to bet and i dont like betting smaller as he will most likely shove all the close hands you are trying to fold out and we dont want to fool around with being on the cusp of bet/folding and bet/calling with our flush draw and less than 2PSB

it feels like you have to pot/call, but it doesnt feel great by any means. if you have strong reads on him you can pull off check/reacting

Your points make a lot of sense, how nitty does the opponent have to be or perceive you to be to consider c/folding or c/calling, or is that never an option?

its definitely an option vs some guys. A lot of straight combos will raise the flop. T96 965 are both probably just getting it in due to some fold equity. but there are still some 986, 654 straights that get there. but vs someone who wont bet with a worse hand than AK on the turn you can probably check fold since it will check through quite a bit