3) The input power, the raw power, is being modulated by the switching
cycle. This generates a transient pulse power on the input lines that
easily couples noise via various susceptibilities into the receivers.

Only if you fail to decouple the input properly.

4) The variable switching cycle, or the varying switching duty cycle,
creates broadband noise.

5) All of which are potential sources of trouble in a communications
receiver that wants to find a 0.16 uV/meter signal in the presence of
noise.

Potential, yes I suppose.
As I said, I know you can make them perform badly, but it's just not that
hard to make them perform well enough that they won't be noticed on your
receiver, assuming you don't make it a practice to connect the power supply
directly to the antenna inputs.

The receiver itself may create more noise than a properly designed switcher.

As a designer of switchers, have you ever had to Qualify a switcher to
MIL-STD-461 and 462?.

That one I haven't. My hamshack dosen't require MIL-STD-461 either. That's
a large complicated battery of tests, that by it's very nature is expensive
to test to, even if you were testing a D-Cell battery.

I have several switchers in use, all commercial designs, and they are barely
detectable on my R-8500 or FT-847. I haven't had to go to any extremes (or
even any measures at all) to quiet them.

My PCs are another matter, they have needed ferrites on the cables, and EMI
absorption material inside the case, but that has proved to be managable.