Can I have multiple heating zones with a combination boiler?
As long as the boiler is capable of providing enough hot water through the system to heat the whole house if necessary you shouldn't have a problem.

What you are proposing is a "coarser" version of thermostatic valves on each radiator and that is perfectly safe for a combination boiler.

I don't think you need return valves.

Make sure that you leave one radiator "open" (usually the bathroom one) so that there is some flow around the circuit.

By the way the fact that it's a combination boiler is a red herring. The "combi" bit refers to the hot water heater, the central heating aspect is pretty much the same as a "standard" boiler with integral pump.

Update

If you want to control the times each room is heated independently you can get combined timer and thermostatic radiator valves - My Greener Home has some for example.