Germans, especially the older generation, are just a bit stuck in there ways and, well, rude. But we all have experienced it in one way or another but it just all depends how you interpret it.
The boy is right. Older people (not just Germans) generally (Oh! How I hate generalisations) take the longest to acclimatise, because they are not used to, and don't particularly like, change. City people are the quickest to accomodate change. Country people can (not always) have a problem even if they suspect that the other person's dialect is from some alien, foreign village, the other side of the hill. I wouldn't let other people's views change yours. Just put your head down and go for it. Try settling in a multiracial quarter of a city, where the minds can be that more open. For Munich I would suggest the Westpark area. There are plenty of shades of skin to go around, but the blood inside is always red. Don't let a tiny fraction of the population put you off. And, if you are from Trinidad, you should fit in well with all the Scots. After all, they all have Trindad & Tobago footie shirts too.