I would say a vpn and that app and a throwaway email address are all you would really need. Proton might have some free servers for vpn im not sure. You’ll never be sure but it’s a relatively inconsequential item so just do your “best” and then stop stressing. A throwaway email and a vpn and using a specific browsers (with Ublock) only for twitch would accomplish similar.
Get Bitwarden and keep all your passwords unique and safe with a very strong password or phrase as your master that is never reused anywhere. That will give you more security than worrying about every site you click on because having an account breached will generally impact your life negatively. Getting a personalized ad here or there is way less problematic on the grand scale of things.
Umm I imagine they limit Amazon JavaScript. Or they could proxy if you weren’t the one hosting. I’m wondering what activity on twitch is so concerning for you? If you just want to “anonymize” your boring normal day to day twitch stuff you can use the one I linked along with a vpn (and possibly proxy to prevent being blocked). Enough in the way that your cringe commentary likely will never be found out. If you’re doing hardcore activism or something three letters would be interested in then twitch is likely not the platform for you lol
The one I linked does need to utilize a headless browser to get an auth key because of how twitch handles auth now. It happens in the background without you even seeing but you have to set it up.
You can set a cookie with any of the tamper monkey type plugins and the “ban” goes away. Not sure if they ban in another manner for account creation, but you can browse not logged in, etc.