Brian, it's not drastically underdone, but, for the best possible flavor, it could use a little bit more color. If ideal coloration is a 10, I'd put this at a 9.75. It just needs the tiniest bit more.
Michael, the brown spots you're seeing aren't all that brown. On a lower quality cheese, the brown spots have considerably more contrast- they start going brown quickly and keep getting darker and darker. With quality cheeses, the rate of browning is considerably slower, so even though you do have brown spots, they're not too contrast-y, and as you continue to bake the pizza, all the cheese takes on a slightly darker, more orange-y hue. Like I told Brian, it just needs a little more color for the oil to be driven out of it and the richness in in flavor to come to the forefront.
Here's a good video on stretching (ignore the rolling pin part):
To achieve an even crust, without thinning in the middle, I've found that the most critical part of the stretch is the windshield wiper part, where he's stretching out the dough just inside the rim.
Here is the dough calculator:
http://www.pizzamaking.com/dough_calculator.htmlRight now, you're close to a .1 thickness factor, which, for authentic NY style, and for getting the most out of your cheese, is too thick. You should be shooting for closer to a .075 thickness factor, which, for a 14" pie, would be a 330 g dough ball.
Now, if you're not comfortable stretching, .075 can be especially difficult, so, while you're learning, if you want to go up to .085 (370 g), that's fine, but maintain an awareness that .075 should be the ultimate goal.
Is your dough doubling by the time you use it? How long are you fermenting it for? You're balling the dough right after you mix it, right?
What brand of high gluten flour are you using?
Oil and sugar are very much appropriate for NY style pizza, and, with lower temp ovens, they go a low way in accelerating browning, decreasing bake times, and not drying out the crumb too much.
Make absolutely certain that the convection fan is on for the pre-heat- listen for the fan and also, if possible, consult your manual. Convection will go a very long way in helping to make sure the stone is saturated with heat in the shortest time possible.
We still need to get to the bottom of why your oven is acting so anemically. A peak temp of 490 in an oven with a 550 dial is pretty horrible. How are you measuring the temp of the oven? IR thermometer?