Hey Beatnik! Welcome to the boards!
You´ll have no problem getting into the mix as you´re traveling, as most of your friends are of different nationalities and ethnicities. I´m a filipino myself, so theres another asian to throw into the mix :P
I think by making the choice that you have, you'll gain wisdom beyond your years. Traveling certainly opens you up in many ways.
It´s a great idea to learn as much as you can, in terms of languages. Interesting of your dad to give you that advice, as he may be right. I didn´t encounter any anti-american hostility, personally, but as I lived in Spain for the last year, I can tell you that 99% of that country(as well as most of europe) was against the war. That seemed to trickle down to anti-US and or anti-american sometimes. Someday, I´ll upload some videos of big rallies in Spain where many people carried sign and banners that weren´t favorable to the USA. Having said that, I know that the sentiments in general weren´t the same for the brit´s. They´re good neighbors.
They think of us as obnoxious and loud. I heard a saying that Europeans believe that Americans speak only two languages- English and LOUDER! Although, I must say that the Spanish should share that prize label too. Sit in any restaurant in France and the loudest table will probably be American tourist with baseball hats and neon shorts.
Here's a post about safety in the General Travel Forum-
Safety.
Teke your moms advice and start building rapport with people from all over the world. Could save you a ton in terms of accommodations and you´ll learn a lot more about their countries before and after you get there. You´ll have a richer experience that the average tourist.
Hope you choose to hang around the boards as many of the members are seasoned travelers and have tons of great tips to help you out B)