I never get myself into trouble without doing a lot of research first
The Leaf uses very little juice with the AC. This can be verified with the energy consumption screen in the center console. It is very efficient and stop and go traffic uses very little juice, too. The heater on the other hand might very well be the first gen's Leaf's Achille's heal. It sucks a lot of power, up to 4.5KW initially since it has to heat up some coolant which is then pumped through a heat exchanger to release it's heat. I held out for a 2012 model which has std heated seats which use a tiny fraction of the dash's heater (~150W if I remember right). I have heated seats in my Golf, too. It makes more sense than pulling heat of an engine trying to warm up.
I don't know about the electrical storm question though and I will research it with my insurance agent and with the service writers at the Nissan dealer. Whatever answer I get I will get in writing! I will also look into a special breaker for the charging circuit. Heck, I'm going to Lowe's right now. (for plumbing supplies.)