You can do this with restrictions in settings-general We have 6 ipads at our store for customers to use and we turned off the app store, disabled the email and set age/rating limits on apps, music, movies and tv shows. I just tried turning off Safari and went back to the desk top and opened the YouTube app, did a search and watched a video. So even though Safari is turned off, wifi is still working. When you disable an app, then the icon doesn't even show up on the desk top. So, go to settings-general, tap on restrictions then at the top of the next page tap on 'enable restrictions', enter a 4 digit code which it will prompt you for a 2nd time to make sure you typed it correctly. Then start going down the list and turn off what you don't want people to have access to. For mail, tap accounts and then select 'don't allow changes' then hit the arrow to go back to restrictions. When all done turning off apps simply hit the home button and you will notice that the app store icon, safari icon and others that you turned off are no where to be found.