I cant login to the alpha because my name has an underscore in it. A normal - works, but a _ wont appear. I even tried copying and pasting into the username field, but the underscore disappears.

Register a new account while in game. I don't think that the game uses the same login information as the forums.

I am having a hard time logging in also, I understood the log in was the same as when you set up for forums. The emails I have do not give me anymore information I have a username and I know the password I use. There is not password reset so I am kind of lost now.

It doesn't seem to be. I ended up hitting the Create Account button from the launcher to make a different login name, and I am playing the alpha now.