"A varying speed of light contradicts Einstein's theory of relativity, and would undermine much of traditional physics." I'm no physicist, but that assertion seems a stretch because if the 'constant is sliding upward, the relative 'whole-universe' relationship would be the same at any given temporal point. Am I confused or what?
The Theory is okay. If the speed of light is not constant, and of course it isn't at all, results may lie outside the Theory rather than contradict it.
Probably. But so am I. If the speed of light is variable, I'll need to rethink just about everything.