Good holiday-cooking question — answering as the UphillTech team:
I don't see anything in the question that is peculiar to pizza dough. Anything I answer will apply to any kind of yeast-risen, glutenous dough. The goal with any such dough is a well hydrated protein matrix that has been arranged in sheets that will trap the gas produced by yeast. If the yeast is dead it won't be able to produce gas and your bread will be somewhere between a cracker and shoe leather- depending on how thick you roll it out. Using too little yeast is not the same as dead yeast. If you use too little yeast (within reason) they will take a long time to reproduce, eat, and blow up...
Full answer by Sobachatina: https://cooking.stackexchange.com/a/20841 (CC BY-SA 3.0).
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