Paradox5240 [he/him,any]
Hard to tell what is wrong from that. I would guess that you skipped some part of the grub configuration. Make sure you do the grub-install above and grub-mkconfig -o /boot/grub/grub.cfg (or wherever your efi directory is). Plus make sure your disk is formatted with GPT (if you are using fdisk just make sure you start with g command that will create new GPT partition table).
Btw this all assumes you are using GRUB, but if you don’t have any reason not to I would recommend using it, it is the most common bootloader.
(Btw I have to say Arch installation guide seems to be much less straightforward than I remember)
As far as I understand, when you use this command, it also writes to memory on the motherboard itself. So even formatting won’t do anything. The boot option will not work, but it will still be there.
Btw just out of curiosity where did you find mention of initrd options in arch installation guide, I just took a quick look and didn’t see it there.
The drive name in boot menu is determined by what you use in grub-install --target=x86_64-efi --efi-directory=esp --bootloader-id=GRUB the GRUB at the end gives it the name and the esp is the directory with boot files, typically /boot. If you like Manjaro, I would probably try to stick with Arch if you want to know your system, it is pretty good distro and AUR is much better there.
To be honest there are basically no left wing parties in Czech. We do have KSCM which is communist party but they are becoming basically irrelevant (about 3.6% in last election and they are projected to get even less in next one). And to be honest they are not the greatest party anyway (although better then the rest). There are few neoliberal center-left parties that are quite popular Czech Pirate Party for example but they are just typical progressive social-democracy type party. And rest is basically right center-right parties.