Doom 2016 was game of the decade for me, but I never finished Eternal after multiple attempts due to getting too frustrated with the mechanics and just not enjoying it.
Going to wait and watch some gameplay before deciding to try it.
Everyone has a different level of tolerance. Personally, Andy can belch all the political crap he wants since Proton is a completely separate entity. But, when the official Proton account doubles-down on views I disagree with (which they've since deleted), that's what crossed my threshold. I've since moved to another service.
Typically, no. AMD (and Intel) are generally plug and play with the same OS install. Drivers are open source and provided via Kernel and Mesa packages.
I do not use EndeavorOS so I cannot confirm if any additional packages are needed for Vulkan support. However, that wouldn't change if you're just upgrading from one AMD GPU to another.
Neat. Here's how you can delete your account: https://www.duolingo.com/help/delete-my-account-and-data