Bad spot, with 4 callers preflop to the initial raise of 80 the pot was just not too valuable at the time to risk it, you barely invested any chips, there is only 480 in the pot before the initial, you could have been severely dominated if someone flopped a set which is always a possibility, even if you hit the diamond you are not risk free! I reckon the pot after the 4 shoves is uber yummy but not worth the risk at that stage with the blinds so low and the relative chances of you having a better spot with a better hand afterwards...
I disagree with your post flop assessment.
The board was not paired.
And calling 80 with a suited A with position along with 3 limpers was not bad.
I know I probably had the worst hand of the 4 at the time of the call but I was making that play to see how the flop developed.
It would have been very easy for me to see where I stood after the flop which is important.
Hitting an A high flush on an unpaired board is the easiest post flop read in all of poker.
I was one card away from being unbeatable barring the board pairing and I had more then enough odds to take my chances.