It sounds like your partition table is corrupted. Recreating it (with parted or fdisk) shouldn’t affect the data. Also, I believe that if it shows up as a block device, you should be able to copy it with dd. dd can write to another block device or to a file (like an iso).

Like a womanizer, absolutely

Even though Arch is very well documented, it’s not really accessible to newcomers. The documentation assumes that you know the basics, so if you don’t, you’re screwed. Mint, Pop! and Debian, to some extent, are much more accessible.

Absolutely, it’s much easier to understand with a binary table

Arch as a daily driver, Debian for my girlfriend and the self hosted stuff, Raspbian for the PiHole