Is the Delta R11000 diverter valve the only valve installed on the wall?

You need a supply valve in addition to that diverter. A valve that can control the water temperature and water volume (on/off).

If the only valve installed in the shower is the diverter, you have no temperature control, and thus no scald control. IF that valve is the only valve you have, it's a bad setup and a code violation.

The Moen 3330 by itself will do everything you need it to do. It will control volume, temperature, and act as a diverter.

As far as the U4929-PK, you don't need to use that at all, especially not with the Delta diverter. Nor do you want to use that without a supply valve that provided proper scald protection.

What you need is a proper supply valve plumbed in before the delta diverter. Do you have one?

Or you need just the Moen valve by itself.

As far as how to uninstall or install things, it depends on what you already have.

Now off on another tangent. IF you have a proper water supply valve and it feeds the Delta diverter, did he install the diverter correctly? If you can remove the trim kit on the diverter so that you can see the valve body that is buried in the wall, the valve casting has "UP" cast in to the top of the Delta diverter valve. Or some valve manufacturers have an arrow to show the desired orientation. If yours has an arrow, the arrow should point up. Make sure he didn't install the valve sideways or upside-down. "UP" should be up.