Sharkbite opinion for my application

I am building out a food trailer. I have my triple sink and hand wash sink in place. I need to run PEX between the water pump, hot water heater, and both sets of fixtures. It’s a pretty short run of tubing overall. If I use PEX, I’ll need to use a couple tees, and some elbows and among some other parts. This is all an exposed area behind a cabinet door (nothing in walls, like a house). It is a very low pressure system we use. The trailer only gets moved once a year so there won’t be any jostling around.

With everything known above, does it seem reliable in my situation for the freshwater? If so, I have a backup question(s). Is it ok to use a 1/2 inch to female adapter coming off the stem of the fixtures themselves or should I combine traditional metal water supply lines connecting to an adapter/PEX after that? I wasn’t sure if PEX is ok to use going straight up to the fixture stem or not (same for coming off the mini hot water heater….metal line or Sharkbite/pex)?