Did I just quote myself?
Silver dude- IMO, your mount idea should work fine. I'm sitting in the garage right now building my mount and using a similar idea. I removed one of the metal channels (the easier of the two to remove). I'm drilling two holes in that channel to mount bolts through it and the plywood base of the slide. On the other channel, I'm using a design similar to the one on the bottom right of your post. All 4 rubber feet will remain in their stock location. I'll post pics when I'm done.
Don't mean to muck up this thread too much but here are some pics of the finished mount. Hopefully it'll help others...
I originally used 5/16" bolts:
Swapped to 1/4" (much better):
The platform sits on heavy duty drawer slides:
And doubles as a table when extended:
So far, the fridge doesn't move at all over bumps and washboards. We're also very happy with the performance of the EdgeStar and haven't had any problems, yet, running it off of our single aux battery.