Like other games such as EQ, WoW (even though it sucks), Vanguard [even though it owns] will warhammer have a offical forum for each server?
No.
Neither we nor Mythic are going to have official forums for Warhammer. We will however support fansites with official postings and dev/community bod presence.
Linking posting to an account would be nice for some parts of the forum but not all of it - questions from potential players for example aren't possible in that environment.
As long as a forum isn't deemed to be "official" it'll be free of most of the "WAAH MYTHIC ATE MY HAMSTER!" whine that you see on the official WoW forums and once saw on the VN Dev's round table - if people think the dev's are reading they will whine an awful lot louder.
There's already a freddyshouse warhammer forum though it's not that busy at the moment, this might change as we get closer to release.
https://forums.freddyshouse.com/forumdisplay.php?f=308
Linking posting to an account would be nice for some parts of the forum but not all of it - questions from potential players for example aren't possible in that environment.
Why wouldn't it be? GOA will most likley link to FH through the WAR-EU site as they have with DAoC, thus FH became the main(most popular) forum for the Euro English servers.