Voltage divider and battery monitor

rickpbush:
One, am I correct in my above understanding.

Yes.

rickpbush:
Two, am I safe using a pot.

Yes. So long as you put it in a place where nobody can see the knob and think, "I wonder what happens if....."

OTOH using two resistors isn't difficult and is a lot safer. You don't have to get it to exactly 3.3V, almost anywhere below that will be fine.