When you punch/drill whatever the hole in a metal lip, how do you keep the back side of the hole from being ragged with sharp edges and burrs? Or do you grind that stuff off?

Just grind that stuff off...or buy your lips from njtackle ;)

Jigman

drill them from the front and grind the back. Back is mostly hidden anyways

grind or emery paper......if you can put something (softer metal or a piece of scrap wood) underneath it, might help lesson the burr. make sure your punch/drill/cutters are good and sharp.

Or just get a vibe machine :D