I'm sure Physicst and Radio Astronomer are quaking in their boots from the blow you have struck. Are you of the opinion that the speed of light has been modified in the laboratory?
That is my understanding. If light can be slowed down that drastically, then one cannot state that the speed of light is necessarily constant or equal when coming from any given source compared to any other source. Between that and the red shift issue, that pretty much blows any confidence in results based on light time and leaves only Geometric projections which are of no confidence over infinite distances. The precision of the angles at base become a guess and thusly precision in general erodes.