VEVOR Commercial Ice Cream Machine 1400W 20/5.3Gallon Per Hour Hard Serve Ice Cream Maker with LED Display Screen Auto Shut-Off Timer One Flavors Perfect for Restaurants Snack Bar supermarkets

Can I use my ice cream recipe instead of water/ premix? The recipe is mostly 1/2 & 1/2 with a bit of whipping cream and egg yolks as emulsifier. Basically, it is an egg-custard which is prepared, then pre-cooled in the fridge for 24 hours. It is fairly thick, aka "crème anglaise". Thank you. (I am tired of using a home ice cream maker which only produces about two pints of ice cream.)

Can I use a premade Liquid mix for ice cream or does it have to be a powder/water mixture?

What is the clearance required for exhaust and/or ventilation? Three sides?

Can this machine be used to make Italian ice?

My local Health Dept requires the equipment to have a NSG seal on it.  Are the hard ice cream machines NSF approved?