According to the specifications, the keyboard layout is "Germany", i.e. z and y in the same place as in Switzerland, but no French characters such as éàè and many punctuation and special characters in a different place than in CH. For more details, simply google keyboard layout Germany or Switzerland. You can set the layout in the operating system, but of course not the key labelling, or you would have to paste it over.

No, and Linux Mint is the ideal solution, I can only recommend it

The RAM in this notebook can be upgraded to a maximum of 32 GB by adding a second 16 GB DDR4-3200 MHz memory module, as it has two memory slots supporting up to 16 GB each. It does not support 64 GB RAM. This is based on the HP 255 G10 with AMD Ryzen 5 7530U having two memory slots and supporting 2 x 16 GB modules for a total of 32 GB maximum memory capacity. The Crucial memory report and HP service manual confirm this configuration and limit. Therefore, upgrading beyond 32 GB is not supported.

According to our information, the USB-C port is only used for data transfer and does not support charging or video output via a docking station. The special power supply unit must be used to charge the notebook and the HDMI connection is required for external screens.

That is correct, neither Windows nor Linux is installed and is therefore left up to the buyer.