It doesn’t solve all the issues you mention, but YouTube Search Fixer [1] [2] is a browser extension that at least lets you remove irrelevant results, Shorts, live streams, and more from search. It makes results a bit more usable.

Disclaimer: I’m not affiliated with YouTube Search Fixer. I’m currently working on https://maxxmod.com, a YouTube-focused browser extension that will include search improvements, so I’ve researched the ecosystem.

[1] Firefox: https://addons.mozilla.org/en-US/firefox/addon/youtube-suite...

[2] Chrome: https://chromewebstore.google.com/detail/search-fixer-for-yo...