There is one thing that comes to mind that is under the dash and controls everything, that is the ignition lock and harness. Perhaps check the connection at the ignition switch and trace the harness to see if a connector is flaky?
BTW, transmission lockout would be consistent with the key not registering as being in the On position, right?

 

Car has been fine for 3 days...it's obvious a connection is loose under the dash. Or course, not all the time.

I've checked the ignition switch/harness...seems fine..nothing obvious. I'll report back if there are any updates, but for now, all is well. And I haven't been able to find anything else wrong.

Appreciate all the help.