I would go, but I would avoid public transportation like the plague. Several people I know have put Canadian stickers on their luggage and belongings when traveling to Europe. Sounds weenie-ish, I know, but a little detail like that could make a difference. Also, watch your wardrobe and hair style. Some Americans in Europe dress in a way that makes them easily identifiable as such. (Ditto Germans, who do the same thing.)
Yep. When our family went to Europe, we were dressed slightly more formally than average; so some people thought we were Germans.