I ve spend two weeks climbing in Kalymnos. I had a fantastic time. Most quality climbs are 7a and up in contrast with say Araps where you can have so much fun on grade 18 and lower. So if anyone asks me I say if you climb 19 and up will have heaps of fun. As for the food I thought it was fantastic and cheap although I am Greek and a: i m used to it and b: I knew where to go. I would suggest staying away from the "touristy" restaurants.
As for Turkey I heard good things about Bodrum which is really close to Kalymnos. Its a bit of a party place, it also has diving and archeological sites etc. Catching a ferry
from Bodrum to Kos (and then another to kalymnos) should be really easy.