Great report - however given the problems you had at AmanZoe I think you are being overly generous in your praise of it. Vegetarian food is very easy to find in Greece given all their fresh produce as is of course fish.
We spent a few hours on Hydra last week - from our base in Spetses ( there was a sailing regatta on - our hotel The Poseidonion was one of the main sponsors and AmanZoe appeared as a minor sponsor) - I love Hydra and I really suggest anyone staying at AmanZoe spends some time there as well Spetses of course.