Yeast can ferment both with or without oxygen.
Yeast energizer is basically just more sugar. Your source of sugar (grapes) should be sufficient enough depending where you bought your grapes, but if you're using the standard off the shelf grocery market, then you will probably need an energizer to bring the alcohol up.
Pasteurization of the must is not necessary if you are immediately innoculating it with a yeast + yeast energizer + nutrients (though, I'd be surprised if you dont get any potential off flavors by doing this). The general idea is that you'd want to get the yeast starting to produce ethanol, add that with a low pH, it should inhibit most pathogens from growing.
For Beer this is a different story, we always boil the must because the pH might not be low enough and you dont want to drink sour beers.
I believe that some wine makers will use absorbic acid and sulfer later on to help stabilize the wine too. Details, unfortunately I'm short on.
in a 5 gallon primary fermenter with a spout, it can be your primary way of doing that first racking. Getting rid of all the other junk in the bottom of the container. You'll see alot of murky yeast cells hanging around the bottom when fermentation happens and it starts to settle. Good for nutrition if you eat it, but not to pleasant looking with some cloudy wine. (not to mention gas when you eat too much of it) You can transfer it to another container to undergo secondary fermentation (like a heavier malolactic fermentation with bacteria) or I believe you can put it into a wooden barrel for aging too.