to demonstrate the reason why 2 nuts are not supplied with the media flow valve its because there would be no room for the thickness of your trap door on your cabinet
Go get the thin flat nut they use on electrical boxes. They come in sizes from 3/4 inch up to 2 inches. Then you can use two nuts and get a very tight fit. I would put the thin nut on top of the door plate and the thick nut on the bottom of the plate. You can also re-thread the nipple so two big nuts fit.
2 are not necessary though only need the one to stop it falling from the cabinet because with it all piped up there is no movement or vibration happening so you don't really need 2 to hold it tight plus the hose holds it fairly still anyway
yes this is correct i decided on the valve with a screw because once you set it you can only adjust it with a screwdriver. some others use a ball valve with a handle but that could get knocked and you could be wondering why it isnt working and not realise it
