The cosmological red shift assumption is indeed in question. The assumption is that the more distant the light source the faster it is receding from us. Could something else than mere velocity cause the observed shift in spectra? Also, this article throws a monkey wrench into the expansion of the universe model since it means the orderly distance measurements and therefore the timeline would be thrown off.
The article only demonstrates that we don't know everything.
Again I'll point to Occam's Razor. The simplist explanation is usually the correct one.
The further away we look, the longer the wavelengths. What causes wavelengths to lengthen? The Doppler Effect, a known, proven and testable phenomenon.
Anything else and you might as well believe in Warp Drive.
Sure, if you're prepared to postulate new physics and to give up energy conservation. You also have to explain why supernovae seem to have developed more slowly in the distant past.
Also, this article throws a monkey wrench into the expansion of the universe model since it means the orderly distance measurements and therefore the timeline would be thrown off.
The most accurate estimates for the age of the universe do not depend on the cosmological distance ladder, but on the WMAP data. Furthermore, even if the distance ladder were all we had, a non-constant Hubble parameter wouldn't defeat the principle; it would simply reduce its accuracy. (The fact that the index of refraction of air changes over moderate distances doesn't change the fact that things look smaller as they get farther away.)