When posting to the forums some HTML tags are permitted, and these are listed below the text entry (reply) box. Could the listing of tags be changed to script links which insert the relevant tag, probably as an open/close pair, possibly with dummy text to be edited by the poster? This would be easier than the alternative of inserting an open tag and keeping track of which tags need to be closed and preventing posting without balanced open/close pairs.
ETA: Mostly for me this would help with the < a > tag, and would insert something like
< a href="url_link"> link_text < /a> because I can never remember the correct format.