1st 5 ports - go with Princess. Taxi to Epheses from Kusadasi as it is not far, ask him to return 3 hours later to pick you up - do not pay until pick up. Santorini is easy. tender ashore, buy your ticket up on the cable car (or walk, do not go on donkey as you will be bitten alive by fleas)
Marvel at the view, at the top of the cablecar, from a terrace with a coffee in hand !!!!!!!! In Athens either arrange over the web or take the transfer bus from the ship (40mins) and get taxi to parthenon etc. Museaums you can walk to. again look at web/tripadviser/cruise critic. Or answers elsewhere on this site.
We loved the donkey up in Santorini and cable down - loads of fun and no fleas. Be adventurous and laugh a lot!