There is AND logic between the setting and whether the user has the specified permission (i.e. the user must have the permission AND the setting must be on AND the user must have censoring disabled in order to not filter words).
A few others for consideration:
Can Save Drafts (u_savedrafts) [if you can post/send PM, you can save a draft]
Can Alter Jabber Settings (a_jabber) [suggest: merging with a_server]
Perhaps merge some of the PM permissions with their posting brethren?
For example, merge u_attach with u_attachpm?






