Re: Want to remove “forum” from permalinks
In general, I don’t think it’s possible, from what I’ve read here.
I’ve read here in the past that the reason for the additional forum in there is that bbPress would have no idea if the slug referred to a topic or forum, hence the need for the second ‘forum’ in the URL. The first one just happens to be the name of the subdirectory you installed bbPress into.
There was this plugin, but I’m not certain if it will work with your version:
Also, Sam Bauers talked about this recently, but I think it was something that would be possible in the future.