Legal Questions Regarding Cohabitation

[JReality]

What is the name of your state? New Jersey

I'm a single male living with my female friend in my house. She pays me $300 in cash a month toward expenses and hardly helps with the household chores. What little I ask her to do, she has given me a hard time about. Lets just say that she's not the neatest person in the world either. I have mixed feelings about the relationship. She's a passive-agressive person that resists trying to do anything on her own toward improving her financial situation. We don't always get along well and I've recently told her that I eventually want to go back to living alone, likely within a couple years, but that she can stay for now. (Note: In the past I did ask her to leave after an argument but she did not want to leave, and I decided to let her stay)

1) A couple of months ago she was diagnosed with high blood pressure (it runs in her family). She's on medication to control her blood pressure, but it's still not under control. She is also a long term cigarette smoker and still smokes. This isn't the nicest question to ask, but was wondering what would happen if she were to get sick (such as cancer) or become disabled while still living in my house. For example, this is a scary thought, but if, say, she ever were to have a stroke from the high blood pressure while living in my house, would I be legally obligated to house her indefinitely and/or would I be legally responsible for caring for her indefinitely if she became disabled?

2) She has lived with me for over 2 years so far. We keep our finances separate. She works as a home health aid and I think she only earns $9 an hour before taxes. Maybe I'm paranoid, but since palimony exists in NJ, I was wondering if I need to be doing anything to ensure my financial assets are protected. For example, would some form of written agreement protect my assets from palimony, or is this a waste of time? Would having her pay actual rental income via a check each month and my reporting as such protect my assets, or would this be an unnecessary accounting hassle? Would my financial assets become more at risk of palimony if she were to live with me beyond a certain amount of years. If so how many years?

Thanks,

Jay