On the hot coax switch question, I suppose it's possible that the mismatch
it introduced was detuning the amplifier so badly that only a fraction
of the normal output was getting to the antenna(s). That would only
happen, of course, if the amplifier had been tuned up with a different
feed configuration. And it would have made the amplifier very warm, too.
I suppose another possiblilty is that the mismatch screwed up the phase in
one of the antennas so badly that everything was radiating in the wrong
direction. In any case, it's quite unlikely that hundreds of watts
of RF were just dissipated somewhere, because that much power really
burns things up fast.