I would like to "reserve" or protect certain user id's. I know I could just register the ones I want to reserve but then they show up in the member directory. Am I on the right track? And if so, can ID's be blocked from appearing in the directory?
ok, dont actually do this until someone besides me says its safe.... BUT.
Manually insert those id's into the database, then delete them. Those Id's wont be used until they are manually used again. So you would have to manually insert them again at some point.
If you want to prevent certain user ID's from being used you can just add that account and then Lock that account. You will still see that account in your members list, and can even unlock that account so you can use it, but others won't see it and can't use it.
If you delete a users that doesn't have any posts yet, the user is completely deleted from the database, and that username can be used again !