Thanks for your input guys!
Yes, jellochaos is right! JimP on podilates is really Jim Picardy in disguise! Dash! You blew my cover!
Yes, indeed. After I started this thread, I thought that I may get some very good answers if I asked the Greeks themselves on a Greek forum. So, I cunningly wrote the word for cycling in Greek, pasted it in Google, and fumbled my way through the forums to create an account and ask for advice. What a great bunch of people they all were! I got loads of input, and I got even more from the email exchanges I had with the Friends of the Bicycle association in Athens. Here's the tread:http://www.podilates.gr/?q=node/15660
After all the advice, I decided to go along with my original route, but keep an alternative route in case it was too ambitious. Here are the links to the maps I created on RidewithGPS:
The main route is this:
http://ridewithgps.com/routes/429931" title="Route

The alternative, less hard route is this:
http://ridewithgps.com/routes/429924

What do you guys think of these routes?
As I said in that thread, I still have a couple of worries: I'm not sure about how to deal with dogs (I know there's a sticky on that somewhere here) and where I can wild camp in safety away from any canine threat. I'm also still a bit worried about getting food and water (although I've been told that there are fountains in most villages) and I'm not too sure about how best to make myself visible. The Bike group says that I should be fine - my bags will make me obvious enough (and I will be wearing a very visible jersey). But would any of you consider getting a flag?