The sausage patty style you refer to is mostly used at Ginos East. Although it is personal preference 1 pound/sausage for a 12inch pan seem a bit too much. I would tend to think 8 oz should be fine. Although i am unaware of the sausage ratio being used at Ginos.
As far as preparing sausage patty, if you are using layered cheese as they do you can simply press it into the pan right over the layered cheese. I scatter about 5-6 sausage chunks over the cheese and press them down and mend them together with my hands. They do not prebake the sausage, it is placed on raw. The ingrediant sequence is dough,cheese,sausage(toppings, ans sauce. I bake my deep dish at 440F for about 24 minutes, the sausage has no problem baking through. Chiguy