Search permissions

If guests can read threads etc, they also can use the search.

A separate permission "Can use search" does not exist.

Quote from spun2u

Any thoughts of adding the option in future builds?

No, it's not planned.

With the following guide the search is displayed in the userpanel only for logged in users (If you know the link to the advanced search, you can still use it!):

Go to Administration -> Appearance -> Templates -> List Templates and edit the template header.

Search for

{include file='searchArea'}

and replace with

{if $__wcf->user->userID}
{include file='searchArea'}
{/if}

Maybe you have to create a new template pack first. In that case, you must activate the template pack in your used style also (Appearance -> Styles -> List Styles).