To be honest I don't think Forgotten Hollow is European at all, it's very generic "spooky" world. Guess you could say it's vaguely inspired by Transylvania in Romania but that's a stretch as the only thing it has in common is a vampire storyline and the head vampire living at the highest point. Other than that there's zero resemblence, FH looks nothing like the town and the builds are American victorian-gothic, not European.
Britechester I suppose you could say is British (as seen from an American perspective though), the modern part is very similar to my university in Britain with the big dorm buildings that are more like apartment blocks and the university being one building in a city area. The older university is more like American universities with the quad and "school spirit" but it looks like it was modelled upon Cambridge (one of the big elite universities for the rich and priviliged) so I guess that works.
San Myshuno I suppose is Asian, but I get more generic city vibes. Could be anywhere. There's nothing identifiably Japanese enough about it to call it an Asian world.