I want to start watching it, but the fangirls are very irritating and it turns me off.
Well, sadly, this is anime. I think that makes it a given. I started watching it before being exposed to any hyper-fangirlism you might find on the Internet, so I didn't really have any prior opinion of it. I will say that it can be a bit confusing since the anime moves rather quickly and skips around in the timeline, so it can be hard to figure out what's going on/who the characters are unless you're about as into it as we are here.
I'm also a history buff, and from what it sounds like, this series is very historically inaccurate. I don't know if I would be able to tolerate it.
I don't think "inaccurate" is an appropriate word. It's just a funny interpretation of historical events. It's obviously not going to be an "accurate" or realistic representation of history when each nation is put into human form. Not one person I've introduced it to has disliked it after watching a few episodes.
I'm going to go out on a limb here and ask if anyone has ever heard of a board game called Diplomacy. I'll just link the Wikipedia article if you're interested, but basically the object of the game is to take control of Europe set in the years before WWI. The players control Great Britain, France, Germany, Italy, Austria, Russia, and Turkey. It's a little like Risk, but the game is based on negotiating with other players rather than dice rolls, so there's no luck involved. I think it would be a good game for Hetalia roleplay, but I can never get enough of my friends interested in it.
Here's the article if you care:
http://en.wikipedia.org/wiki/Diplomacy_(game)