RE: VERY confused about what charger and equipment I need.
Based on what I have seen here, the answers to all of your questions are here if you look. They ceratinly have AC/DC chargers capable of charging more than one battery at a time (I've seen them but don't know of any specific brand), they do tend to be more expensive(in the $200+). What you need to look at is how many total amps they can charge each battery at. Some of the multi charges only charge eac battery at 4 or less amps which is going to mean a longer chrage time. Turnigy has a 4 port charger that will charge each battery at 6 amps but it is DC only. I use to balance charge my batteries each time but since I moved to bigger battery packs, I gone to fast charging at the field and balance charging at home. Fast charging halves the time it takes to charge the batteries and thus far has not caused any issues.