Well, I can't exactly answer your questions, but I'll give you some of my experiences. I went in August and I flew into Athens, took a day trip to Delphi, flew to Rhodes and Santorini and got stuck in Mykonos when the ferries weren't running due to high winds. It was hot--I mean hot! Like, oh my god, it's 95 and we're going to climb to the acropolis where there's not shade and my clothes are soaked and there's no air conditioning anywhere. But it was worth it. I love ruins and sightseeing and I think there was the most to do and see in Santorini and Rhodes which were both incredibly beautiful. You can be happy in both places for 2-3 days. I thought Mykonos was boring. Definitely have to see the Acropolis in Athens and go shopping around it. Delphi was a nice day trip in an airconditioned tour bus, but a lot of walking and climbing, and, yet again, no air conditioning in the museum there. The islands are gorgeous and most can be covered with a one day stop. Except for Crete which is bigger and I hear very very nice too. Just some of my thoughts. Have a good trip!
