Read "Starlight and Time" by Russell Humphreys, Ph.D. at Sandia National Labs (retired)
Ahh yes, the master of "there are no voids in the universe". By this same reasoning, given the vastly different mediums that light would travel in this magical universe Dr. Humphreys discribes, new stars/galaxies/pulsars/etc.. would be poping up over time. To the best of my knowledge, this is not happening.
I might add, if this "magical medium" of unbounded matter did exist, then we would be able to see EXTREEM changes is rotational spins of pulsars in short periods of time while the medium thru with this light travels also moves due to gravity. But since pulsars are known as the watches of the universe, I do not put too much "faith" in Dr. Humphreys assumptions. The last part is VERY important since, as you claim, the universe is only 6K years old. In order to fool us as the universe does, there would need to be MANY differing layers of this magical medium where light travels at different speed. So fluctuations would not take the millions of years to see, but only a couple, if not daily, since you place all of this happening in only 6K years.
Based on what sample time? Your existance, perhaps 40 years? The eighty years we have had higher-tech instruments to study the stars? The four hundered or so since the invention of the telescope? We are using a much grander timeframe that we have data to support if we are talking about the God-driven forces needed to create stars.