Again. All easy stuff. It is doable. Its not that hard. And it can be done for a reasonable cost.

Home Depot sells water tubing that is food safe, obviously since its for ice makers and other potable water sources.

For the build plate, experimentation would be involved but I bet you could attach a kitchen cutting board/sheet to the platform and extrude onto it thus isolating the build plate (non-food safe) from the extruded food safe filament.

As for transporting it.. go to a restaurant supply or even GFS/Sam's, they sell plenty of food safe containers to store and transport things in as well as storing the filament in a food safe container.