there are those settings in forum permissions.
it is by group then forums.
So it may e best to create a group for those special people and give the more rights than normal users.
Or make them a moderator of that forum.
so if you want to update a group.
you can edit all of the forums there.
Goto:
cp>>permissions>>Groups
find say the "users" group and select forum to the right.
in particular look for
Edit post time limit
Set it to so for a year it would be like 525600.
also look at
Can delete post while you are in permissions.
