560 sl climate control / blower
 

2 problems: (1) turn ignition, engine starts, but unless I back off the key just a click toward off the climate control won't kick-in, blower or cool air, (2) back off the key and the cool always comes on, but sometimes (erratically) the blower won't come on for about 8 - 10 minutes (sometimes more, sometimes less), then functions normally for the duration.

You have a worn ignition switch. Replace the electrical portion of the switch before attempting to diagnose anything further.

absolutely agree.