Yeah both vbulletin and IPB have an option to allow you to lock your own threads, through group specific or global options. I believe you can choose so if a thread is locked by a moderator/staff it can not be re-opened by a normal user.
Unlikely to be granted to groups (granting that also wouldnt make sense). The only real thread ownership perms desirable to add (speaking for the viewpoint of all parties) would be thread renaming, and even that isnt as desirable as post deletion. Being able to rename your own threads/stickies is nice (to update the version numbers in it yourself, such as to mention the latest version number, or date of last edit).
FAQ threads themselves dont need to be closed, at the core (and are editable by non-mods as long as open).
point is i don't want people responding in the faq threads, i want them to start their own, and having to pm jonc or someone to unlock a thread so i can edit and then pm them to relock it is a chore for them and myself.
Questions/comments about the FAQs themselves would belong to one actually (it is not like such threads wouldnt or couldnt get cleaned from spamish posts cluttering them).
If threads closed, the norm is to PM mods/admins about it anyway.