Setting up buddypress with correct permalinks

Just as I think I have a handle on WPMU and my theme of ?blog I come accross this:

Is Buddypress a plugin a them or what?? -couldn't find the correct place to post this -please advise :slight_frown:

Moving on... I wanted to use buddy press extended profile and the invite anyone feature. To do that BP is asking me to change the permalink s from its default setting. The problem is that when I do that I get dozens of TAGS that give broken link results. How to I satisfy BOTH requirements of using all the BP feautures and have no broken links reported by bots?