Unrelated. If you can't login to character page, just go ingame and do Q-M-P-S.
As for
I actually have it the other way around.
Since the name change I can't directly log into the forum but have to log into my account/character page and take the link from there to the forum.
I am not sure, but, if you had managed to login to forums directly with a password/username, i think it might be that your username may not have changed itself, only your display name, as a separate thing. Have you tried logging in with both benkei and Molly as username?