It definitely works on a MacBook Retina with MacOS 12.5, and it works very well. But that only helps you if the compatibility problems only come from the OS.
My 2017 Macbook Pro also works with the supplied USB-C cable. Why shouldn't the 2018 one work? Disconnect everything from the power supply... otherwise make a Genuisbar request to Apple!
Yes, that is possible. Plug & Play with USB-C cable. This monitor has an USB-C port for the connection. I can recommend the following product: Aukey USB Type-C Nylon (C - C, 2m)
This Monitor is actually made to Charge your Notebook and Display a Screen at once only with one Cable. I think it should work. But i think you should better google it cause im not 100% sure about it.
Doesnt really mean anything as far as were concerned :) Often each european country has a designated manufacturing number for the same model. best is to compare specs
https://www.digitec.ch/de/Comparison/5925501-5810236-5890665