Good boring Debian
So, it only took a few hours to replace my Manjaro setup. The advantage of being an old Linux user is that I learned to split the partitions (or another disk) and put the most important data there.
The funny thing is that the GPU problems that I experimented on the Manjaro setup are also in the new Debian setup. So, that probably mean that they're driver related or my GPU is toast. Well, now I need to figure out how to check that in my new install, track in the logs how the error happens and if they're really driver related, at least I hope so.