1) You should replace, in the hack instructions:
}elseif (strlen($message)>$foruminfo[forumpostchars]) {
with:
}elseif (strlen($message)>=$foruminfo[forumpostchars]) {
otherwise, if someone posts the exact same number of characters as is set for that forum, no update query is run at all, and you might get inaccuraces in your usertable (postcounts not matching usertitles anymore, etc. etc. etc. etc.).
The > has to be >=
2) I don't get it - where / why does this hack add one query? I don't see an additional query Anywhere
Good idea for a hack, but I'm gonna implement a different version (basically just a fixed minimum-char-amuont, not forum-specific. Don't need to edit any files except newreply.php and newthread.php

)