Vincent,
Your assumption that everything we believe about cosmology is "dictated by the simplicity of the calculations of the astronomers" is something with which I have to respectfully but quite vigorously disagree. The reason is that astronomy, though considered an off-shoot of physics, is an observational field of study. Nothing in astronomy can be assumed until it is first looked at. In my estimation, that has been the general population's discomfort with the science. And for this reason: The telescope as we know it has been around for only 405 years, since 1610. You probably have buildings in your town older than that! Consider this: The "modern" human eyeball connected to the modern human brain on the other hand is, perhaps 400,000 years old, and the foundational hominin brain, 4 million, give or take. The very notion we live in a huge old universe hasn't even made it to the century mark. In all, our brain, evolutionarily designed to view the cycles of the day and night, the seasons of the years, the tracks of the lights in the night sky across the arc of the blackness, I think is having a very difficult time just coming to grips with the fact the earth revolves around the sun, let alone that we are part of an island universe, one among billions.
Astronomy and biological evolution are very much "up-start" fields of study, even though astronomy and biology have been studied for thousands of years. So, there is in my mind no underestimating the shock our species is experiencing trying to assimilate the enormous changes in world-view being demanded of it by the observations astronomers are making and the implications for the universe we inhabit.
What you have been advocating, if I am understanding you correctly is the theory of Redshift Quantization. It was indeed strongly advocated by Arp (whose catalog of anomalous galaxies is in standard use by all astronomers:
https://en.wikipedia.org/wiki/Atlas_of_Peculiar_Galaxies Dr. Arp identified 338 galaxies that did not fit the standard catalogs. It was first published in 1966. A number of galaxies in the Arp catalog are visible with amateur telescopes, and several of them are also Messier Objects, which are all visible with a reflecting telescope with at least a 180mm diameter mirror, for a price well below 1000 euros. As you point out, other astronomers such as Dirac, Johannes Koelman, Christof Wetterich, along with K.G. Karlsson, Wiliam Tifft, and numerous others, all mistrusted the redshift quantizing as was published beginning with Hubble's original research.
Tifft, who became one of the leaders is quoted:
William G. Tifft was the first to investigate possible redshift quantization, or "redshift-magnitude banding correlation", as he first called it.[14] In 1973, he wrote:
"Using more than 200 redshifts in Coma, Perseus, and A2199, the presence of a distinct band-related periodicity in redshifts is indicated. Finally, a new sample of accurate redshifts of bright Coma galaxies on a single band is presented, which shows a strong redshift periodicity of 220 km s−1. An upper limit of 20 km s−1 is placed on the internal Doppler redshift component of motion in the Coma cluster".[15]
Tifft, now Professor Emeritus at the University of Arizona, suggested that this observation conflicted with standard cosmological scenarios. He states in summary:
"Throughout the development of the program it has seemed increasingly clear that the redshift has properties inconsistent with a simple velocity and/or cosmic scale change interpretation. Various implications have been pointed out from time to time, but basically the work is observationally driven."[16]
https://en.wikipedia.org/wiki/Redshift_quantizationIf you check the link to Redshift Quantization, you will find that it went through several period of experimentation through the end of the century, but it was the incredible data gathering power of the Sloan Digital Sky Survey that, for all intents and purposes put the idea of redshift quantizing to rest.
In 2005, Tang and Zhang:
".. used the publicly available data from the Sloan Digital Sky Survey and 2dF QSO redshift survey to test the hypothesis that QSOs are ejected from active galaxies with periodic noncosmological redshifts. For two different intrinsic redshift models, [..] and find there is no evidence for a periodicity at the predicted frequency in log(1+z), or at any other frequency. "[7]
A 2006 historical review of study of the redshift periodicity of galaxies by Bajan, et al., concludes that "in our opinion the existence of redshift periodicity among galaxies is not well established."[27]
In 2006, M. B. Bell and D. McDiarmid, reported: "Six Peaks Visible in the Redshift Distribution of 46,400 SDSS Quasars Agree with the Preferred Redshifts Predicted by the Decreasing Intrinsic Redshift Model".[5] The pair acknowledged that selection effects were already reported to cause the most prominent of the peaks.[7] Nevertheless, these peaks were included in their analysis anyway with Bell and McDiarmid questioning whether selection effects could account for the periodicity, but not including any analysis of this beyond cursory cross-survey comparisons in the discussion section of their paper. There is a brief response to this paper in a comment in section 5 of Schneider et al. (2007) [28] where they note that all "periodic" structure disappears after the previously known selection effects are accounted for.
What is very special about the Sloan Digital Sky Survey is that its data is open to everyone. It is open source. So any astronomer with any theory can download the data...wait a minute...any 12-year-old in the world with a big enough hard drive can down load the entire SDSS database and revolutionize the field of astronomy is she is smart enough. I point that out to emphasize that doing cosmology using the tremendous resources of the Sloan neither requires big buckets of money or a big light bucket professional telescope.
Here is their link:
http://www.sdss.org/ They are currently on their 11th Data Release.
So, my good friend, Vincent, when I say to you with the utmost respect that I am confident the universe is expanding, I am saying that based on the work of some thousands of incredible astronomers, who have spent their lives just not doing what was convenient for their field, but were every day trying to be on the cutting edge of hominin history to help each of us try to comprehend (even themselves, included) what it means to be part of a universe that 4 million years of anthropothecus evolution was centered on one very singular rock in the middle of the entire universe. It's gonna take that brain a while to catch up with the reality of what these folks keep seein' on the other end of that eye-piece.
I tried to put in a YouTube vid here, but I couldn't make it work. Which is the pitts, 'cause it was really cool, man!"