Glad to see all the newby questions and good coaching in this thread! Nope, 12 amp charging (or any AC charging session) will not automatically stop prior to 100% like a DC fast charge, unless you program a limited duration session with your remote. I have a super-versatile EVSE that will charge on either 120V or 240V at 12, 16, 24 or 32 amps, and unless I'm travelling and using lesser circuits, I always charge to 100% and leave it set for 32 amps max so that visiting EV friends can charge faster. Our i-MiEV won't pull more than 16 amps regardless of the circuit capacity.
I'll second the route less travelled. I make a round trip every Saturday morning that would be 59.8 miles with a lot of interstate highway on the "Shortest Time" default setting for most routing software, but can be accomplished in 48.4 miles on surface streets that are predicted to take only 12 minutes longer but are much more reliable time-wise, compared to the construction delays and soul-sapping highway traffic jams that often pop up during weekends. I consume significantly less energy on the shorter, slower street route.