@johnnydoe: In your theme’s register.php, before the line
if ( is_array($profile_info_keys) ) : (above the
<?php tag before that), put:
<?php unset( $profile_info_keys['user_url'], $profile_info_keys['from'], $profile_info_keys['occ'], $profile_info_keys['interest'] ); ?>
That will take out the extra fields in the register form. What you did was take out the part that outputs all the form fields
I can’t see the “to participate” part either, did you manage to get hold of the bbPress.org template?