prepared crust is fine.
not sure about the ricotta
you are cooking it 1 hour total. 10 min at 400 degress and then 50 min at 350 degrees
probly 3 days in fridge, freeze is fine, then thaw and heat a short time in microwave
I would stick with the correct amount of eggs so it will set up properly like a quiche is supposed to
powdered milk fine
hope it is tastie!