Buddy press Plugin

I was trying to register for buddypress.org, however I was not able to do so. The error message states that I am already registered and kick me here. So I have not choice but to ask my question here regrading this plugin.

I seem to have a lot of blank screen so is this plugin compatible with WP 2.8.4 since they require MU but I have the idea that it has been integrated.

So is installing BP to WP 2.8.4 the same as WP MU?
The integration of BP is using BB forum, however I am using simple forum, can I actually integrate with simple too.

I hope some one out there can help me.