https://github.com/bennyclams/untube requires infrastructure but allows you to download youtube and non youtube videos

if you're willing to pay, just get an email through microsoft, you'll spend a lot of time and headache making a selfhosted email server work the right way consistently, it's not a good choice for business/money making if that's what this is for.

I'm running the *arr stuff for TV and movies, plex, postgres for whatever needs a db, reverse proxy and a video downloader for non-tv content that *arrs cant find like youtube or patreon

Reverse proxies are generally used for HTTP/Web services, but I think that nginx can proxy tcp connections as well, however I've never used this functionality. You could possibly also take advantage of cloudflare tunnels