Wow ok. So even if you met an amazing woman you got on with, if she didn't have play video games or watch Anime you'd reject them? Seriously, you need to think of your priorities before you enter any serious relationship because it doesn't sound like many of them are gonna end well
I don't think you need to be so specific with your requirements. If they don't like Anime, then that shouldn't be a deal breaker. As long as they're not forcing you to stop watching /liking those things, you can like different things.
I work as a Sysadmin for a web host who sells VPS's. I've helped many people setup domains on their server to cover SPF, DKIM and DMARC passes on a daily basis. Most use these for personal or business level mail delivery without issue.
Are there hurdles to overcome? Sure. But it's not exactly hard as long as you have a IP that's isnt a poor reputation (which as an ISP we help delist and improve). But it's not impossible.
Its more "convenient" to use a third party mail provider just as Office365 since you pass on all that setup and responsibility onto their framework, but it's not hard to setup a decent level of mail service yourself.
If your using steam, you can go into game properties and set Proton as the compatibility tool. Depending on the age of the game, you might have to switch versions of Proton.
You can use https://www.protondb.com/ to check the compatibility issues and suggested versions by the community for specific games too.
I'm actually pooping now, but ok.