The outdoor unit looks like it belongs there, and those corner pads (which Escape uses because the liner material wouldn't fit the interior shape otherwise) are certainly handy!
The rubber isolating mounts look like a good idea... as long as it doesn't tilt forward and backward with the accelerations and decelerations of travel. I don't know how stiff they are.
That's a substantial plate of aluminum. I don't know if I could stand to hand over the price of that, but it will certainly protect the bottom of the unit and provides a solid mounting platform. Dave, have you considered a lip along the front edge to protect the unit from stray stones off the road?
With the outdoor unit behind the propane tanks, is the plan still to add a removable cover for travel?