Hi Mozzer ! We stayed at the Hotel Platinista in Psalidi(just outside Kos Town) a couple of years ago and spoke to people who had maried there. They married in a hall but had their reception (traditional Greek ) in the hotel. They had "pin the money on the bride" "plate smashing" and "dancing on the tables while setting fire to the ground" We were there during the evening reception and it was absolutely fantastic.

Yep.
Kefalos on Kastri Island
Its great you get a boat over there.

Stella at keftours@hol.gr can organise everything for you.

Good luck

If it helps.... I have put a full page on getting married in Parga on the Parga.com website. Though primarily aimed at that resort, the rules, regulations etc are pretty general for all of Greece. Hopefully it might help with your plans