Thanks for the advices guys. I’m indeed very concerned about grounding, since I had the issue already with my shop vac.
In my opinion, worst case scenario, I could use a few 12V batteries to power up the ramps, so that they are on a completely different power network with the cutter. I have shielded cables but I didn’t put them to ground, maybe I’ll do that if it turns out that I have issues.
For leveling, I will probably build a new bed just for that, since I cannot use the wooden one anyway.
I’m not concerned too much about it, but that may be because I’m totally inexperienced. Anyway, I think I can find some solutions to overcome this issue, either by lowering the amperage, finding a good way to clamp everything , some active cooling or just by increasing the cut speed (the MPCNC can move pretty fast from my experience).
I purchased my cutter today, I hope it 'll work!
I took the cheapest one, 40Amps version, here:
It is supposedly ok for a maximum of 12mm steel sheets, which should be more than enough for me. I think those things can cut any kind of metal, right?