I believe there's at least one basic fallacy in your development.

The problem is that a directional antenna can't be made to take up zero
space. Let's consider a situation where we can have complete
cancellation of waves from two sources. There surely are many others,
but let's look at this one for starters.

Consider two identical vertical omnidirectional antennas radiating
equal, out of phase fields. There will be a plane of zero field passing
directly between them, where their fields sum to zero. My challenge is
this: Devise a directional antenna which lies entirely in this plane and
which has a response that's different for the two antennas. That is, an
antenna which has a stronger response to the field from one antenna than
the other. I maintain that you can't do it. Your directional antenna
must extend beyond the plane, where the cancellation isn't complete. And
it's there where it gets its signal to deliver to the load, and where it
can distinguish between the two fields.

Also, any antenna placed in a field in a way that it delivers a
detectable signal to a load alters the field. That's a second potential
problem with your development. However, I believe that the first problem
is enough to invalidate it. If the initial analysis of fields in space
is invalid, and I believe it is, then the extension to transmission
lines is based on a false premise and is questionable.

I maintain that there is actually zero field at a point of superposition
of multiple waves which sum to zero, and that no device or detector can
be devised which, looking only at that point, can tell that the zero
field is a result of multiple waves. This is a very important and
fundamental point, and I'm glad you brought it up. If you or anyone can
devise an example where a directional antenna can be placed entirely in
a region of zero field and yet detect that the field is made up of
multiple fields, please present it.

I am, of course, assuming that everything in this discussion takes place
in a linear medium.

Roy Lewallen, W7EL