HVAC Question................. Is AUTO the best setting?

OP has more questions now than before asking what Auto does.

I remember the old ICE idling around 800 rpm at the stop light during the wet snow of fall and spring with headlights dimming and fan slowing noticeably and having to rev to a 1000 to get normal behavior back. Googy is a good way to put it
Battery technology is strange, especially when something in the car is setup improperly. The kicker is learning howto work around the issue in the best easiest way possible. Oh, I do that too! Not in the Prime though, not yet anyway.

 

I meant to add above, with the older 06 and 02 cars I religiously turn off - heat a/c wipers rear window defroster - at red lights for battery health.
12 volt in the 02
and 154 volt in the 06 civic hybrid.