I do lightly spray my pies with EVOO before baking.
Like I said, if this is just about avoiding saturated fat, drizzle the evoo, don't just lightly spray it. For a 16" pizza, I'd use as much as a tablespoon of evoo. It will completely change the nature of your part skim mozz, both from a melting standpoint and a flavor one. With a tablespoon of evoo, the cheese will transform from mediocre to sublime.
Besides adding oil, another way in which you can help the cheese melt better and give off more flavor is by lightly misting it with a spray bottle. Water + oil will go a long way in making the pre-grated cellulose stuff work well also. In English muffin pizzas, because the cheese isn't getting heat from below, it melts horribly/doesn't bubble. In those rare instances where I make english muffin pizzas, I'll grate the mozzarella, put it in a bowl, add water and oil and then spoon this wet mixture onto my pizzas. This melts far far better than the grated cheese. Even thought the cheese gets clumpy and has to be spooned rather than sprinkled, the nice thing about this is that the cheese is evenly covered with oil.
It's been a solid 10 years since I tried soy cheese, but, at the time, I wouldn't feed it to my worst enemy. From what I understand, the technology (casein, aka 'elmer's glue'
) hasn't changed much.
I've also tried fat free mozzarellas and and those were even worse. Perhaps the light mozzarella Peter mentioned is more palatable.
No matter what cheese you go with, if you're allowed to slather the pizza with evoo, do. There's no free lunch here. Fat is flavor and meltability. Without some form of fat, mozzarella is going to suffer- big time.