I also tested this on beta 4, but when I got to the end and tried to add a new forum my add new forum option in the admincp was now broken.
Under enable/disable features it now has a blank line with a yes/no and after that there is no longer a save option.
It also seems that maybe one of the hooks had been added to beta 4 already? I don't know coding, but when I went to edit the forumdisplay.php file I noticed some changes from what you had listed to search for and what was in the actual php file.
I think it was this
Code:
eval('$threadbit .= "' . fetch_template('threadbit_deleted') . '";');
}
else
{
$show['moderated'] = (!$thread['visible'] AND can_moderate($forumid, 'canmoderateposts')) ? true : false;
eval('$threadbit .= "' . fetch_template('threadbit') . '";');
}
which isn't the same in beta 4 I believe.