Good thinking. Note the air flow in the unit is at both ends and you want to be able to get at the holes in that one side, so your cupboard venting should be more on the sides too, but a vent on the door can't hurt. The more venting the better. And keep the dustballs from gathering at the converter's end vents.
You will need good light to see to operate the screwdriver in the holes. The switch on the left is quite small and not very robust so don't poke at it real hard. You don't want to be on your hands and knees twisted around in a small space trying to do all this, so another location might be better.
You need two lengths not much more than five feet each
of #4AWG copper (not cu-al) to the battery to ever see the 75amps, but just to run the RV 12v at 13.6v, you can go longer with thinner wire, so another location might be easier.
