I don't know much about the EU, what its benefits and detriments to the UK were, or which countries want to stay and leave the EU. But from what I've heard, staying in the EU would have made more economic sense for the UK. Now that the UK has basically stood as Bisharp to the EU (Defiant), you're right, it may embolden other nations to want to leave. Ultimately, as you say, it will take a long time to see any drastic change. If the UK even ends up leaving. None of the politicians are moving forward on this, they're just dragging their feet on the whole thing.
Well, here's hoping that after your secondary schooling is done, you'll get the opportunity to take courses here in the Great White North. I'm not much of a nationalist; I could care less for national pride or the whole "my country is better than your country," etc. There are some things I'd want that Americans have that Canada lacks, but ultimately, I feel much safer in Canada than I think I would in the US.