I think both languages are spoken in Brussels.
And yeah, Belgium is a mess. But the people are nice.
Maastricht is an awesome city. The people speak a language amongst themselves, but they speak regular Dutch too - only with an accent. It'll probably sound more pleasant to you.
Frisian is an official regional language derived from Dutch, as well as Limburgish (which is spoken in Maastricht). But only the people in those specific regions speak it, and they're often (and incorrectly) referred to as dialects. Limburgish has a few variations too. The language in northern Limburg differs from that in southern Limburg.