The only way forward for Qubes OS on laptops - is to use modern 11/12-Gen Intel CPUs or AMD alternatives. Those can run youtube in 1080pX2 properly.
I do not have that, probably also a problem of outdated CPU of T480.
The recommended list of laptops should definitely be modified to avoid outdated devices.
At least to limit applications of internet (GNU/Linux still has no proper per-application firewall, 20 years passed and none, Windows has dozens). And limit other activities. E.g. when you enter password in keepass or copy password of anything to the clipboard - all applications has access to it. For me that is unacceptable level of lacking simplest, basic security from GNU/Linux.
None that I know of. A couple of projects existed in beta stages but died. I also do not understand why some people wrongly consider Tails to be an alternative to Qubes OS as it is VERY not a one.