Keep the seal clear of toppings and sauce, and use water to stick the crust to the base. Wet flour is a great glue, tomato sauce and cheese are not.

When I make my own pizza I use the spare sauce as a dip. Bit of olive oil and fresh basil over the whole thing makes the crust pretty much as nice as the rest.

Also for the stuffed I think you have to do more of a burrito roll type thing so that the edge is trapped by the weight of the stuffing.

I like to do new Haven style pies. With those there isn't much crust in the first place, so I try to spread the sauce as close to the edge as I can