I can't fold a fold here against a half stack. flush draw missed so I do expect them to turn up with busted draws some % of the time. Would be folding 100bb but not getting away from this hand.

I agree with Harvie, folding vs this stack size seems completely out of the question given the amount of missed draws that have missed. I would have sized up your bets on the turn however to allow a comfortable pot sized jam on the river, as well as to maximise our value vs his flush draws.

This is a fold for me preflop. ATo is my weakest offsuit ace from the CO

I'm never folding this when a shortstacked player can easily be doing this with many weaker Ax combos. I do think you should have bet a bit bigger on the turn though to avoid the overbet shove on the river you should have been planning.