Ok, I think I won this battle. Garuda was successfully installed.
Turns out the core of the issue was my Windows installation. As I mentioned in OP originally my SSD was MBR and then I converted it to GPT. I thought that Win10 will figure everything out by itself but no. Even when I used flash drive with Win10 it couldn't repair the system because it couldn't find one on my SSD. I had to reinstall Win10 and make sure that it understands that it is installed on GPT disk. Once I did it I installed Garuda alongside and this time there were no errors.
Now with that said I still have an issue with system freezing once in a while and then unfreezing after monitor wakes up. I guess it has something to do with open source drivers, so I'll have to test it out.
Also in case any newbie like me with the same stupid Asus BIOS will have similar issues to mine, here's the list of settings:
- Boot -> Boot Configuration - > Fast Boot: Disabled
- Boot -> CSM -> Launch CSM: Enabled (if you disable it, most likely it will re-enable itself after rebooting)
- Boot -> Secure Boot -> OS Type: Other OS
- Boot -> Secure Boot -> Key Management -> PK Management: Delete Key
- Advanced -> SATA Configuration -> SATA Mode: AHCI
After that booting in UEFI mode with open source drivers option should do the trick, although it needs something like 15-20 minutes to skip this screen
starting version 249.2-1 arch
That's it. Thanks to everyone who answered my questions. You're awesome!