I'm just back from Greece Peloponnese, Greece mainland, Macedonia, Albania and back to Greece. Ferry from Venice to Patras and a return to Venice to Igoumenitsa...do it, you'll love it and not regret it !
We camped everywhere except Venice with absolutely no problems and people everywhere were friendly or even over friendly, had to get a new fuel pump for the 1150 in Albania and it really wasn't a problem apart from the language barrier ( learn some German ).
Join ADAC for breakdown peace of mind but if you just go to Greece Carol Nash breakdown would probably do, CN won't however provide insurance cover for Albania or Macedonia so you have to take your chances and buy at the border ( I was 50 miles into Albania before I could get any insurance as they wouldn't sell me at the border
), Albania costs around 15 Euro for 2 weeks but Macedonia is 50 Euro for the same duration, although probably far better cover !
Watch out for crazy road surfaces and stolen manhole covers
It would be easy to spend 2 weeks in the Pelopponese alone as the mountain roads are amazing and with very little traffic, mainland Greece and Albania also surpass alpine scenery as far as I'm concerned...did I say that the roads are virtually empty away from the coast.
Go with an open mind, be polite and courteous and you won't have any problems.
Same goes for Romania, Bosnia, Montenegro (bit like Slovenia but full of tourists on the coast), Hungary, Slovakia and Czeck Republic..all excellent to visit and an even better experience if you keep away from the main areas and travel through the small country and mountain roads.
It's back to the Pelopponese next year with a little sprinkling of Turkey this time