I live in North Carolina, and I am not sure what the laws around this issue are. I was looking to purchase a home: live in one room, and rent out the other. I am quite a germaphobe, and have had incidents where people leave the water running, use too much water, etc. so if possible I'd rather avoid letting tenants use my bathroom. There is only 1 bathroom in the home, so I was planning on using that for myself and having a "Port-a-potty" outside the home for the tenant to use. If I were to purchase a home with 2 bathrooms, it would increase the house cost by $15000 and I'd rather not pay that. So is it legal to NOT have an accessible bathroom for the tenant in the home?
According to North Carolina legislation, lack of an operable bathtub or shower in a rental property constitutes a dangerous condition that must be immediately rectified by the landlord, even if the tenant accepts that it’s not provided.
Roommate shares are tough
I've done housemate shares for 15 years. It is not for you. Your mindframe, what you are expecting to get out of it and what you are willing to put into it, is simply incompatible with the concept.
I imagine from your point-of-view that you have never been in a housemate share, and that's too bad, because "climbing the ladder" starting as a non-master tenant is how you get the feel for how these things work. Trying to become a master tenant "from a cold-start" is a recipe for disaster. You don't even know how to vet a good housemate or how to present yourself so they can vet you.
Every room in your house will be "commons space" except your bedroom and (by your plan) the bathroom. How will you feel about the person entertaining friends in the living room? What happens when the housemate brings a girl/guy over for sexytime? Their guests won't know the bathroom rules! They will be in your kitchen cooking food on an almost daily basis - do you really plan to have double pots/pans, double silverware, two toasters? Are you really sympatico paying utilities when they bring in a waterbed and window A/C that they never shut off? At least splitting the phone bill is a thing of the past, that was never fun even with housemates I really liked.
Your solvency and your ability to own a home will be riding on this, and you'll be scared and grouchy. They will make you crazy. You will make them crazy. The whole experience will be awkward and uncomfortable, for everyone.
Consider truly separate spaces: In-law or duplex
What you need is a place that has an "in-law apartment" legally cut out of the original house. This has a separate entrance, a proper bathroom with shower, and some sort of kitchenette to accommodate the other parts of state law for what qualifies as a habitable space. The government will force you to provide those things, or they will condemn the occupancy until you fix it. In-laws can be rented as full apartments and command a higher price than housemate shares -- but they often don't have separate meters, so you end up forced to provide free utilities.
Another option is to buy a duplex. This is a house built from the ground up to be two separate units, and typically the units are roughly equal. They are metered separately. This being a full and proper apartment (and with only one shared wall), it fetches a good rent, equal to or above a similar sized apartment. It's very common for a first-time homebuyer to buy a duplex, live in one side, and rent out the other.
With both in-laws and duplexes, the homebuyer plans renting the unit as part of her financial plan to buy the home. She also enjoys a variety of tax advantages as a landlord that are not available to a homeowner - for instance a homeowner cannot deduct depreciation and maintenance, but a landlord can (even if the unit is not occupied)! Yes you have to pay income tax on the rental income, but hey, more income!
You have to run the numbers on all that, and consult a tax advisor if it helps, but I think between the higher rents collected and the higher tax deductions available, a duplex or at least an in-law has significant financial advantages over a share.