Is analog & vinyl anoying? Is it worht it.

I agree that most music lovers probably dont have these kinds of systems, this is a hobby and the equipment research and sound production go hand in hand, it appears most all men are nerds just we all have different passions.
There are the Model Train nerds, Civil War buffs, Coin and Stamp nerds, Photography, aquarium, fishing, hunting,
even Harley riders are nerds about their bikes.....the list goes on and on because we are all better off if we have a passion and some vehicle for a reasonable dose of
Obsessive Compulsive behavior.

Viridian...Some recent tests that I ran on my humble phono system (Shure v15mr) suggests that, to my surprise, some signal up to 35 KHz does actually exist on some records, (at a very low level) so I won't contest your suggestion that 45KHz is possible. The low end is, IMHO, the important difference relative to CD. For a CD there is no roll off the bass to limit groove modulation amplitude, or mix to mono to prevent stylus hopping, or feedback. And, my ears still work quite well down to 20 Hz, but are deaf (to sine waves anyway) over about 14KHz.

Regarding dynamic range, on my system the noise floor of a "silent" groove is about 80 dB down from the peak of a loudly recorded LP, and a similar test of a CD yields about 100dB. I admit that I didn't read your reference (web names that go on for two lines are a challange) but the ones that I have seen usually talk about listening to signal that is many dB BELOW the noise floor. Frankly I don't enjoy listening unless the quiet passages of music are well above the noise floor. A signal that lies well below a noise floor can be detected by computer processing and perhaps by ear, but I would not include that in a practical measurement of dynamic range.

Viridian...I agree that it is astonishing that a mechanical media like a vinyl LP can sound so good. With some dynamic equalization (instead of the fixed RIAA curve) it can be as quiet as a CD, and with reduced distortion. (This was the DBX LP system, which I once had).

I believe that the CD4 system used a carrier with frequency modulation above 20 KHz. Because it was FM an undistorted waveform was not necessary. It was intended that the rear channels have full bandwidth capability (20 to 20K) so the cartridge had to work up to 40 KHz. In fact, although CD4 was a flop, phono cartridge design was greatly improved as a result of CD4.