Hi Patrick, as long as the access rights management hasn't changed too much since 8.4.3, this should be relatively easy.
First, remember this: once a permission is set, it is denied to everyone else, so even if you set one page to be invisible to unregistered users, that page will also be invisible to all other users, unless you explicitly state that others may see it. The group problem should be simple: Unless the top page is the "Main" page, go to the page, go Settings -> Administer Page -> Rights: Page & Children There you can explicitly set group access rights. If your top page is "Main" or another page containing technical subpages, only set the Viewing permissions to the Page, NOT its children. No anonymous access can be set on Administer Wiki -> Users & Groups -> Rights in a checkbox labeled "Prevent unregistered users from viewing pages..." To remove the Sandbox, simply set the top pages viewing permissions to "denied" on unregistered users, that should remove it from the view of all others as well. For the rest, check Administer Wiki -> Extension Manager -> Installed Extensions for the etension you want to remove, and remove it with "uninstall". Word of warning, though, this CAN break your layout, as some extensions seem to have a greater effect on the default pages than expected. Good Luck ;)
