1) H265 codec gives a better quality in video. It is a fact. Does h265 codec in uploading video on Youtube give better quality in Youtube than h264 codec which is officialy mentioned by Youtube as a good practice and a recommendation?

Here you can see a comparison of the final file sizes (in gigabytes) of the different codecs used for this experiment. This helps inform your choices, as bigger files will mean longer upload times to YouTube.

The SAME video has BOTH a 2:1 24FPS transcode AND a 16:9 30FPS transcode made of it. Stored separately on YouTube’s servers as the “best” quality options, presumably for different means of distribution. This is a first for me, but I’ve certainly seen other wacky stuff like this before.

This was surprising to me. While I didn’t have much faith in the quality of Apple’s compressed codecs on my M2 Ultra Mac Studio, I expected NVENC HEVC to perform better here. It’s seen major quality improvements over the years and in my overall testing, is quite a powerful encoder. Something’s off.

I'm not sure how HWBOT API detection works on real unlocked parts - they are usually detected by diferent name than original. If it is not detected properly and you have to type the name yourself, then it should be also possible to select actual unlocked status. If it is detected correctly (like X4 960T) and editing after submission has been uploaded doesn't work, there is one workaround. Instead of saving the datafile and manual uploading later, you can upload directly from X265 and there is an option to disable CPU detection. In that case it should be possible to choose correct CPU and core count.

Upload in the best quality you can, and don’t worry about it. YouTube quality is constantly changing and evolving, and there’s no real way to min-max it other than to upscale your videos to 4K for maximum bitrate/quality transcodes. Beyond that, don’t worry about it.