Cutting depth it's important to get your zero right - which it's important to have your work flat Make sure the needle is fully extended when setting your zero - it's easy to bump it and then you wind up cutting deeper than you thought.
Setting up marlin to enable a servo output doesn't affect use as a normal CNC. It's just there when you need it. As long as you don't send the gcode commands to enable and set the servo it doesn't do anything. If you search this thread for my posts with 'servo' in them you should find details on how I set it up.
Same for the vacuum table, I've posted photos and I think even a link to an OnShape project for cutting it. It's just 3 sheets of foam board. One with horizontal strips cut out, one with vertical, and one with holes where the strips intersect. I cut all three out with the needle cutter then glued them together. Then I cut some openings in the side to fit a vacuum plenum that I think @rockyboy shared previously. Again - search on our posts with 'vacuum' and you should be able to find it.
Setting up marlin to enable a servo output doesn't affect use as a normal CNC. It's just there when you need it. As long as you don't send the gcode commands to enable and set the servo it doesn't do anything. If you search this thread for my posts with 'servo' in them you should find details on how I set it up.
Same for the vacuum table, I've posted photos and I think even a link to an OnShape project for cutting it. It's just 3 sheets of foam board. One with horizontal strips cut out, one with vertical, and one with holes where the strips intersect. I cut all three out with the needle cutter then glued them together. Then I cut some openings in the side to fit a vacuum plenum that I think @rockyboy shared previously. Again - search on our posts with 'vacuum' and you should be able to find it.