How much output does each workshop produce. How many shops can I keep stocked with a single workshop?
This depends on several factors.
I've noticed that what Workshops produce is dictated by what the closest shops are. This seems to be somewhat random, as Workshops will sometimes choose to produce goods of the closest shops, and sometimes, they will choose to produce goods for shops clear across the map! The best way I've found to mitigate this problem is to build them to a 1:1 ratio. Build a Workshop, a road, then the shop, all in a line. In this manner, it seems that the Workshop will only supply the single shop.