[xwiki-users] Disable Registration and View Default Skin at Login

Hello, I would like to disable registration so wiki accounts must be created by an admin. I followed the instruction on this page: http://lists.xwiki.org/pipermail/users/2016-February/032129.html to only have Register checked for the XWikiAdminGroup, but users are still able to register and log in. I can't find the Guest user to remove the Registration right from that user as well. Does the Guest user still exist in 8.1 and is that still the correct way to disable registration? I would also like to display the default skin on the login page. This page http://lists.xwiki.org/pipermail/users/2011-July/020305.html recommended allowing unregistered users to view the default skin, but I have checked "Prevent unregistered users from viewing pages, regardless of the page or space rights" on the Administration: Rights page which seems like it will override any permissions I set on the default skin. The page that looks like it should be the right one is bin/view/XWiki/DefaultSkin, but clicking on the sprocket only gives me the option to "Administer Parent".  Is there a way to enable the default skin for the login screen while still disabling unregistered users to view anything other than the login screen? Thanks, Jared