Question about long-term house share/friendship and legal responsibility

Location: Washington

I'm sharing my house with an older friend. We've been friends for over 20 years. We used to date. We stopped dating at least 10 years ago. Sometime after that he moved out of state to his daughter's house, came back here to visit in 2020 which turned into permanent residence in my home. That's a long story in itself, was not exactly what I had in mind but I let it go because of the pandemic it was hard living alone. He helped with bills and food and a little bit of company during the isolation.

He does not pay rent, he pays two of the utilities and now starting to pay a third cuz I've asked him to. It was about half of the utilities expense but now it will be more with the third bill he's agreed to pick up. Also food cost we know is crazy, he buys a lot but I still buy a lot of my own food maybe 25%? He has bought things for the house, vacuum cleaner here, paid for furnace repair there, pays for my oil changes because he takes the car in for me, etc. I was including this... I'm not sure if it's relevant or not.

We have no shared accounts. At one point he suggested I put his car on my insurance policy cuz his was expensive and I pushed it off and he hasn't mentioned it again. I was thinking liability not a good idea for me to pick up as I am a homeowner and he is not.

My question is, as friends have suggested to me, that I may have some legal responsibility for him. A lot of people assume we are a couple. But we are not we have separate bedrooms and we've been just friends for years. But I do worry cuz his health is not good if there is any sort of legal issues that I should concern myself with. I didn't think so but several people suggest there may be because we've lived together now for over 5 years.

He has family, a daughter out of state who as far as I know is POA but generally uninvolved. Has missed Father's Day, birthday, death of best friend (I let her know cuz I thought she would call and console), and Thanksgiving, has not called. Also I have reached out with questions because she has access to his health care / my chart but she is not responded. Total garbage. Also a son who lives in state he does have contact with every couple weeks or so as best as I can tell. Someone suggested if something happens to him I'm responsible for his health care cost, whatever else, etc. WTH?

I don't want to bring this up with him. He won't admit it but I'm sure he's hurt by his daughter literally getting him to sign everything over to her and then removing herself from his life. I don't feel like I should have to spend money on a lawyer but I'm sure the daughter is really lawyered up. Her and hubby have at least four homes at my last count, tons of money which seems to rule their lives, it would not surprise me at all if they tried to push anything and everything off on me who is just getting by and hoping to retire by full retirement age. Really need advice.

Sorry, I know that's a lot. It's definitely a unique situation and I appreciate any insight. Thanks!