Jeff Wisnia wrote:

How would that plumbing arrangement fail to work?

It would sure fail if that "aquarium" he talked about placing the
condenser in didn't have a completely sealed top, city water pressure
would make it overflow in a jiffy.

No. The aquarium would be unpressurized. Its water would flow through one
side of the plate heat exchanger, with pressurized water on the other side.

And when he said, "when/if the tank water heater completely fills", I
assume he meant to say, "when/if all the water in the tank comes up to
110F temperature".

Yes.

He didn't mention how he was going to handle switching the water
heater's original heating source back ON when he didn't need A/C.

We might just disconnect the bottom element.

Removing the condenser fan blade would provide a minuscule reduction in
motor power consumption...

I disagree. Rhetorically-speaking, an assertion demands no more than a
counterassertion. Then again, perhaps you have numbers?

Nick