I'm trying out the Lehman Pizza Dough Calculator and am wondering how the amount of active dry yeast affects pizza dough. If you use a higher percentage of yeast, will the dough be airier?
Maybe, maybe not. It depends on where you are starting from. Unfortunately, there really isn't a simple answer, and getting to where you want often takes some trial-and-error.
More yeast will make your dough rise faster, all other things being equal. So will warmer temperatures. There is a mathematical relationship between yeast quantity, temperature, and time. To give you a better idea of what I mean, I quantified it here for a typical sourdough culture: http://www.pizzamaking.com/forum/index.php/topic,22649.0.html
If you are looking for additional lightness (even light texture like white bread), it may be a simple matter of adding a little more yeast and keeping everything else the same. If this works, it might imply that perhaps you simply are not currently getting enough rise as things are. You could probably get to the same place by warming up the dough a little as it ferments or by letting it ferment a little longer.
If you are looking for a more open structure (large open holes in the crumb), using less yeast and fermenting longer at a lower temperature often helps. You still take the dough to about the same level of rise (in the ballpark of double the original size) you just let it take longer to get there - probably a minimum of 12 hours and 24 would be better. The other thing that really helps achieve an open structure is heat - particularly conduction from the bottom - such as in a hot pizza stone.