A simple tag around the IP link in include_post_display.html will do the job. You just have to add this arround the IP link:
<% if current_user_status = 3%>
That solution is not 100% safe, since a moderator could go around it if he knows well Gossamer Forum. But that should be OK for most of the moderators.
Adminstrators can delete, move and edit all posts in all forums.
Moderators can delete, move and edit all posts only in the specific forums they are moderators.
Sorry for my english...