Normally I don't allow user name changes on the forum, because then we have to manually go into the database and change the user name there in addition to the forum so that the profile works and links with the new user name. In short its a pain and it wouldn't be fair to allow one person to change it and not another.
Jayne, If you have posted some things about yourself that make you uncomfortable, then the best thing to do would be to go back and edit the posts to remove whatever material you feel wasn't the best to share. If your unable to edit the posts, send me a PM and tell me which ones and I'll be glad to do that for you
The update of rules and forum/internet safety was just to keep people mindful, for their own protection. No need to get paranoid, especially if nothing has come of any of the things people may have posted in the past. The community is rapidly growing so it seems an appropriate reminder.