Re: difference between permalinks
Well, AFAIK, bbPress only allows three values for permalinks: true, false and slugs. In config.php, there is a line (around line 27 in the current 0.8.3.1 release I think) that starts
$bb->mod_rewrite =. I think it works like this. Of course, you can try modifying your config.php and see for yourself as well.
$bb->mod_rewrite = true;
$bb->mod_rewrite = false;
$bb->mod_rewrite = 'slugs';