This suggests that if all the electricity used to refine fuel was simply used to charge vehicles instead, there would be sufficient generation capacity (on a global basis) to power electric cars and that all emissions directly from cars would in effect be eliminated.
Yep!
What you have to remember is that not only do you need a lot of electricity to operate an oil refinery, you also need a lot of water - and pumping water around is also a massive consumer of electricity. In the UK for example, the water industry uses something like 15% or more of the total UK electricity generation capacity.
If only we had access to a limitless supply of free and clean energy from a Fusion Reactor. It would have to be absolutely huge of course, in order to meet all our needs. And for safety's sake it would have to be sited a long way away from centres of population. Maybe someone could figure out a way of putting it up in the sky?