Pertinent questions slikmrs, comes to us all eventually. Very brief answers to your questions:
Yes you can be buried here, most cemeteries have a foreigners section. No, as far as I know, you can't be cremated here. Yes, you can have a body repatriated for burial but I believe it is very expensive. As to terminal illness care, well there is an old peoples home in Fethiye but I don't know if they accept foreigners, and I guess the hospital care for the terminally ill would be the same as the UK, provided you have insurance or the funds to pay for it. Though as Karennina says you may have to go to one of the bigger cities for specialist care.
As Scunner says, try not to die here !!