I was able to create a child theme of bp-default using the instructions above. I just imported the stylesheet, and copied header.php and sidebar.php and tweaked them a bit. Worked a charm! Thanks
“The default theme isn’t intended to be used on hosted blogs on a WPMU install, so the links do break as you’ve found.”
Oh… I see. Thank you! With that information, I have now found this and will give it a shot (I guess it’s obvious, but I was just confused about how it was supposed to work):