you can edit posts in one of two ways
the quick edit icon (3rd icon at the bottom of your posts) which allows you to edit without changing screens
the full edit icon (4th icon) which takes you to the advanced editor.
your own posts can be deleted (5th icon) however mods will still be able to read anything you wrote. if personal information was listed editing your post before deleting it is best.
to change the title of your thread you just edit the first post and there will be a spot for title.
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if a user submitted information that was too personal (address, phone number, complete real name, credit card info or other very sensitive information) then you can pm a mod to take a look. if the information is unsafe to post in an open thread we can take care of it. not so sure "settings" are really all that personal enough to warrant an issue unless it includes the above sort of information.