As far as the doors coming open during travel, our residential fridge has 2 doors on top and a freezer drawer on the bottom. The freezer drawer seems to drop into a small recess in the glide mechanism when it's fully closed, so there's no problem with it coming open. DRV took advantage of that by supplying a Z-bracket that goes behind the top of the freezer drawer and in front of the double fridge doors to hold them shut. They also supply 2 velcro straps to use on the fridge door handles as a backup. That has worked fine for us.
We really haven't had problems with stuff moving around in the fridge. Maybe that's partially due to the MorRyde independent suspension and the TrailAir tri-glide pin box, but stuff in the 5th wheel doesn't seem to move around in transit.
Rusty