christianj, great minds think alike. I have just booked nearly an identical vacation this June at all the same stops, 2 nights at the Grande Bretagne and even picked hotels from the non-wood properties you listed.
As for Athens, I have been there for work before. You can see just about everything there is to see or do there in a total of 2-3 days. But the Hotel Grande Bretagne is in an amazing location.
-Wayne