BuddyPress.org

“First the buddy press plug ins don’t install correctly until you go and reset a value in the wp_sitemeta table in the database. “

If you had to do that, then something’s up with your install.

“could you not distribute a default theme with the plugin or at least mention it somewhere? “

uh, they did. There’s a parent theme in there, a default child theme and in the instructions both in the readme.txt and all over this site it explains how to use it.