Favorite airport
If I was doing this flight from Blackpool I would make the first stop Jersey, that any you will get two bites at the duty free fuel cherry.
France is no trouble and I would recommend Cannes as a night stop, hotel on the airfield and a quick taxi ride into town. Get fuel as far south in France as you can, that might be a stop in Figari on the south of Corsica.
Italy is bad news for GA.....and it gets worse the further south you go so refuel as far north as you can, I found Perugia quite good.
From Perugia I went directly to Corfu, and refueled.
A BP fuel card makes you popular with the fuellers as it cuts down the paperwork and minimize the chances of the Italians ripping you off.
Skiathos is wonderfull check out if the skid marks are still on the end of the runway that were the result of an MD80 who seriously underestimated the difficulty s of landing a jet airliner at the place, he avoided going off the end and 30 feet down onto the beach only by executing what looks like a handbrake turn.
At one time I was going to Skiathos twice a week, a great place to kick out the automatics at FL150 and fly a 79 tonne airliner like a C172.