Wood – How to drill through a metal screw in the cabinet doors

Yes, the drill chuck will mar the finish of the shelf. There is a slight chance of damage to the chuck. Plus, choking down on the bit, like that, obscures your view of the hole (the drill and chuck block it) -- making precision harder to accomplish.

The correct way to do this is to use a drill stop.

Drill stops are less likely to slip than tape or zip-ties, and are much better for precise and/or repeated drilling.

If marring the finish is an issue, clamp a piece of 1/8th plywood over the site and adjust the drill stop accordingly.

PS: A piece of wood over the hole is usually a good idea anyway, when drilling finished surfaces. It helps reduce both splintering and the scratching that occurs when flakes of drilled wood or metal whip around the bore site.

Cut that pipe out in 2 places. One place is above the bottom shelf of the new cabinet and mid way between the 2 fittings on the upper pipe that goes at a 45 degree angle. Recouple it back together when the cabinet is installed. The supply lines need to be relocated too, but you may be able to move them around to get past their issues.

The cutting of the vent pipe is still taking a small chance it will be difficult to get the pipe back together. As it is you will need to shorten the pipe you cut out at least by a 1/2" to make room for the stop built in as part of the coupler. You will also need to account for how much out of square the cut has too.

If the upper portion of the pipe has a little upward give to it, it will be a lot easier to rejoin. If not you will need to be really assertive on getting it back together again.