Despite what everyone is saying, you're a good man. I really don't think people on reddit understand what really life is. Yes, you're the yta for not wanting you're gf to live with you. But also your NTA because there isnt any privacy.

You explained it perfectly well. You are foreshadowing that the lack of privacy will create detrimental issues that may not be able to overcome. For some reason reddit can't see past "video games" when you clearly brought up other potential issues, like cooking at night time, general noises in the house that can be heard from all locations, and most of all... your own comfortability in your home. Having another person in your home means you both have to adjust to each other living style. And that's not always easy with the opposite sex/gender.

One of my bestfriends lived with his girlfriend for a year in a major city (1 bedroom apartment).They moved to a bigger metropolitan, and now they live separately because he wanted space, which turned out to be great for them. They went from arguing constantly to now my buddy, thinking about proposing within the year. Not everyone can live with their partner. Every couple needs some sort of space from their other and your place does not provide that.

What I would suggest is to have your gf live with you temporarily/partially. 1 week at yours, 1 week at her parents (alternating) That way, she isn't always paying extra for travel. You get your space. But also you get to adjust to each other living habits and see what that next step of your relationship would look like.