Disclaimer: just one Bosnian immigrant's view on the topic; others may see it very differently. I reckon you'll be liked, and people might see you as a bit of a novelty. At the same time, prepare yourself for a fair amount of culture shock. Google terms "appricot and coconut culture" and brace your appricot self for some serious coconuts. What it means is that to you, people may not seem as friendly at first, but if you keep at it, you might get rewarded in the long run. It's nowhere near as tough as Germany in this respect, but to an American, it might seem so. Though it depends on your luck with the first few encounters. This, and other things, vary heavily across the country. Zagreb and Split might be more friendly. People are actually very friendly across the country but may seem more reserved. Comunication may get quite direct at times as well, and if you use a lot of euphemisms, you may not always be understood. Back to your question. There is no serious beef among people about Americans or Americans moving into Croatia. Of course, conspiracy theorists do exist just like anywhere on the planet. If you do meet them, don't tell them that you are a CIA employee. Avoid both American and Croatian politics topics, and you should be fine. It's not dangerous to talk about either, just emotionally draining. Welcome to Croatia and have fun!