4--tonearm/internal wiring. similar to the turntable, the tonearm is an ancillary component that in terms of sound quality works best when you don't experience anything from it at all;
The Tonearm has two functions, which is both as a mechanical device and supply a means to transfer an electrical signal generated from the Cartridges Operation. The Main Purpose of the Tonearm apart from be a device to mount a Cartridge on to, is for the Tonearm to function in a manner that enables the Cartridges mechanical operation to function without impediments that will impact on the critical movements. There are numerous designs for the Tonearm and all will to some extent be an impediment to the Cartridges mechanical function.
How the Tonearm has a design to manage transferral of energies are quite varied as well, but in general all Brands, Models and Designs are not equal.
The other purpose of the Tonearm where it is supplying a means to transfer the electrical signal generated within the Cartridge, also has quite an important consideration, as an incorrect wire choice and configuration for the wire within the Tonearm can impede the mechanical function of the Tonearm and present a resistive force to the required freedom of movement. The quality of the cable and cable connections for being able to transfer a unadulterated signal is a more difficult subject to broach on and this will be adopted mainly and accepted as the chosen method that is supplied by the Manufacturer. There are some who change the supplied method and produce their own bespoke methods.
5--interconnects. the difference between wirings seems overblown;
My experience has shown that there are benefits to be had by having tried out a selection of Signal Wire Types and Cable Designs in a system.
The choice for connectors used on the Cable and the Chassis is also a worthwhile consideration.
If the connections are causing a loss of the complete signal being transferred, the signal loss will arrive as a sound at some stage, and it can be detected as a smearing to the details. The more information that can be delivered on time, the more the detail of the envelope of a note and vocal is present and detectable.
I'm sure the description offered will be challenged for the suggestion the impact of the connections on a Cable, but when the changes in detail retrieval are detected, and the method used are seen to be responsible for the impact being made, there are not too many descriptions left to explain what is being perceived.