You're point 5 is mimicking what Darwin said in that his theory breaks down if something irreducibly complex was discovered. I am here to tell you that we have already discovered it.
See number 16 on my list. Not everything Darwin wrote is accepted by evolutionists today.
And that is their assumption that there MUST have been a precursor to a function, but this begs the question... what was the precursor before the precursor. There is always an origin.
In terms of the first cell, there is agreement that there was a minimum standard of requirements. For example a cell cannot exist without the mechanism of transcription and translation being operational, (as well as other systems). Transcription and translation require many different parts, hence in order for the function to be utilised these parts must have existed... An experiment to test this could be to have cells with all their helicase genes removed. Or how about the genes coding for polymerase, or what about ligase... I am sure if you had a cell with one of these components missing it would die.
Models of protocells suggest that RNA preceded DNA. This is backed up by research demonstrating that RNA can serve as both a template and a replication enzyme. Furthermore, empirical studies show that RNAs can undergo selection, influence cell membrane permeability, exhibit heritable differences in reproductive success, and take on new enzymatic functions as a result of sequence mutations (see the articles I have linked below for more information). Therefore, primitive cells may not have required transcription and translation. Instead, they may have depended exclusively on RNA.
Compounding this are the systems that require other systems or parts in order to be functional at all. In terms of cellular respiration glycolysis requires the citric acid cycle in order to dispose of its product, (since a build up of its product- pyruvate will lead to a pH change eventually killing the cell... It also leads to a slowdown and eventual stop in the system). Whereas the electron transport chain requires the citric acid cycle and glycolysis to supply NADH and FADH2, which in turn replenishes NAD and FAD to be re-used... (if these are not replenished the system stops automatically).
What if there were redundant biochemical reactions in the cell? The reactions of the citric acid cycle may be the most efficient series of reactions, but like most chemical processes there are multiple ways to get from point A to point B. Evolution does not suggest that the citric acid cycle evolved step-by-step in an organism that was already dependent on it... that would be impossible, and we are aware of that. It could, however, evolve step-by-step if other enzymes and reactions existed that are no longer present in cells today. Furthermore, primitive cells may not have required the full set of reactions that cells today depend on.
Now what this means is that celluar respiration cannot come about via a bit-by-bit method that Darwin proposes, hence just as he says his theory falls apart. Yet what do evolutionists do? I haven't seen anyone investigating how cellular respiration "evolved" hence my claim stands that the evidence against evolution is ignored, (or if it is addressed it hasn't been given much attention, downplaying the problems I guess)
When you say that it hasn’t been given much attention, what sort of attention are you referring to? Just because there hasn’t been a PBS special devoted to the evolution of cellular respiration, doesn’t mean the research isn’t out there. I did a quick search on Google Scholar and got quite a few results.