I never heard of a battery or alternator causing an engine to stall

Look somewhere else.
Have you replaced your fuel filter?.
How's your cold start injector?
Have you checked fuel pressure?
How's your idle control valve?
Any vaccum leak?
Get back to real MB plugs.
You said

ist rotor and Bosch wires only few yrs old
......don't assume they are perfect. Check/test them.