gremlins......common or different problems
 

It all started with the car (coupe W123) not shutting off.
Within a few days, it wouldn't start with the key. Now
it is getting really hard to start, but seems to be turning
over just fine when jumping the box on the fender well.

After jumping it with the bimmer(oh the shame) to increase
amperage, it did fire off this morning and I pulled the battery
@ work and tested it on the mac tester. It was at 12.79v
and 663cca.......is this enough?
It is giving the impression that the glow plugs are not
working as they should, but the dash lite cycles as it should.

Is this an ignition switch problem? or multiple problems?
any way to test the ign. switch?

For shutoff-Check to see if you have vacuum at the shut off on the IP when turning the key off. If not it might be a leak-do your door locks work? Or some malfunction with the ignition switch vac control.
For hard start check your glow plugs at the junction box connector with an ohm meter. They should all be under 1 Ohm. Does the glow plug light come on?

yes, light comes on and cycles as it should