I try to give end users as much freedom as possible.
Both yes and no. We actually us it to inform our user when their iPads are out of date. When a new update comes we let the users know and if they don't update their iPads the devices background goes all red. Ounce they update it can be set to whatever the user wants it to be.
no, we don't. But while the initiating rollout / enrollment, we serve a company wallpaper to the client and set it as default. The user can change the wallpaper, if wanted. The same procedure we do with the Dock. The users dock is configurated, but the user can change the dock items if he want.