Yes, there's a few ways to do wireless charging. Given that in this context we're talking about inductive charging and that's what I was talking about(even though I didn't specify it) I'm not sure why you're bringing up the other ways.
When you're making a charge array as large as that for a wireless car, it's actually quite efficient over the relatively few inches from the charger to the car's receiver. So the losses aren't 'huge'.
Now, you're actually right about the additional batteries - when I last read about these ideas, EV batteries were running about double the expense per kWh, so minimizing them was a consideration.
As for gas and diesel powered buses - there's several problems with them: First, diesel has gotten a lot more expensive over the years, though it's currently in a valley. Electric could be cheaper(if not for battery expense). The second is pollution - the more combustion we can get out of the cities, the better. Third is maintenance - said buses are used enough to get quite expensive, EVs can actually be more durable.
Of course public transport is the best if it is cost effective and convenient and unfortunately I have yet to see or hear of a city where this is the case.