First, let's deal with this:
I have tried to go to support but I can't log into the gameforge support system because it does not recognize my log in info even though the same info works for the RoM website.
The Customer Support website doesn't automatically accept the same credentials as the main site - you have to register there before you can log in. You can choose to use the same username & password or different combination if you prefer, just be sure to use the same email address as your game account.
Since you're having trouble with the GameforgeLive installer, you could try the alternative download links provided by Inferiority - see the 5.0.5 Client link in my signature.
Make sure you configure the Region/Language to log in to the US servers as I believe the default is the European servers.
The browser version of RoM is currently only available to the European servers which is why your US account info won't let you log in.