1. 1mm lip is nothing, you can go beyond that.
2. 2 years
3. when i was a VW Dealer tech, i would recommend replacement if the pad material was thinner than the backing plate it's glued to
(~3-4mm). the thinner your pads, the quicker they heat up/overheat.
4. 2 pairs of the
6 Ton Stands and a
floor jack from O'Reilly's. you have 3 in concord.