Re: Way not merge bbpress and BuddyPress into one Software and get new dynamic?
Agree with you on the option.
Rather than using “forums” slug for group forums directory, I will rather use it for external forums. Instead, I will consider using group-forums slug for that.
Again, why use two copies of bbpress if you want external forums, why not use a single copy but with the tighter integration.
Well, why I said It should not be Integrated.
Currently,Is there anyway for the site admin to manage all the forums on a buddypress at one place.No.
Can You manage all the topics from one place, no , you have to visit individual groups to manage it.
bbpress has been in existence ,before even the conception of buddypress,so how about the people who are already using it as a standalone software,or on their wordpress/wpmu site.We may not force them to install buddypress for using/keep using forum.
I hope ,There are other various reasons why It should not be merged.
But again,I too wish ,there should be more better integration. 
