Anyone ever made their own pizza sauce, and have you ever used STEWED tomatoes in the can, or ......?

Stewed tomatoes are too watery as they come in the can. You can certainly make pizza sauce from them as long as you cook them long enough to dry them out. Tomato sauce and paste skip that step since they are drier to begin with. Pizza sauce is really pretty much the same as tomato sauce for pasta but needs to be drier and more highly seasoned, because watery sauce will soak the crust and because you use so little that it needs to have lots of flavour or it disappears on the pizza.