(2) The massive history of the UK IMCR is apparently regarded as irrelevant,
Far from it. I think without the "massive history of the UK IMCR" FCL.008 would never have got off the ground. The relatively safe operation of UK pilots under the IMCR regime is the safety justification by which the competence-based IR is justified.
What the heck is an "emergency IFR approach" - either it's an instrument approach, or it isn't.
In the same way that you would expect a PPL to get a few hours of instrument flying and to perform an "emergency 180 degree turn on instruments", without giving them privileges to fly intentionally in cloud, it doesn't seem unreasonable to give EIR holders some "emergency" instrument approach practice without giving them privileges to fly instrument approaches intentionally.
being able to go into airways with the EIR will be a benefit, a considerable benefit to a few individuals
That's a very UK-centric view of airspace. Only the UK has this peculiar reverence for "airways", in which the easiest instrument flying takes place (hold a level, fly a heading). Everywhere else, you just use the airspace that's there. The hard part of instrument flying is the approach, which is why the EIR holder has to go to some lengths to ensure that they don't end up flying an approach in IMC.
I've never really understood the concern expressed here. If I have an IR, I need my destination to be above minima, otherwise I divert to my alternate. If my alternate is also below minima, I'm left in some difficulty, and may have to use my "emergency skills" to get down safely. If I have a PPL, I need my destination to be VMC, otherwise I divert to my alternate. If my alternate is also below VMC, I'm left in some difficulty, and may have to use my "emergency skills" to get down safely. If I have an EIR, I need my destination to be VMC, otherwise I divert to my alternate. If my alternate is also below VMC, I'm left in some difficulty, and may have to use my "emergency skills" to get down safely. What's the difference?