Martin:
Same reason I hated the brick patios and sidewalks I had when I moved here. Nothing wanted to roll on them, and the worms kept putting up castings between them so that they sank.
I'd love to have several of those rolling pots; saves buying furniture dollies. As for the rain barrels, go to some resale place, or Craigslist, and look for pickle barrels. The Greeks ship both olives and pickles in brown barrels shaped like the old time whiskey barrels. They have a (believe it or not) screw top that can be re-used, they hold about 40 gallons (a bit smaller than the pop syrup barrels) and are not unattractive. They would make excellent rain barrels and can hold enough perch or goldfish to eliminate the mosquito problem. (I just trapped and relocated a few green sunfish this morning to take care of a mosquito problem)
Those are nice looking fig trees.
Ox