@Lindsay Henning
People rent out rooms all the time. Think of it as if your parents own the place and are renting you a room and you can use the common areas. Your parents are your roommates, they can come and go as they wish and use the home. They should respect the one room you are renting and you should have privacy there. (you should have this in a lease).The rules they have for you should be in the lease. The issues you suggested above are very common and there are always expectations for the renter and lessor. If you don't like the rules, don't live there. Landlords cannot discriminate against specific groups of people. We cannot say in our leases that no white skinned people or black skinned people etc. We can say no drug use or smoking or drinking on the property. Drug users are not a protected class. We can restrict who enters the property. I have a clause in each of my leases that my tenants are allowed to have guests but they cannot be at the premises for more than a specific amount of time. A landlord could have the rule of NO guests. They can put cameras on the property. They can have noise rules. They can enter the premises with proper notice and inspect. They can charge fines when a tenant doesn't comply with the rules. They can charge you for the damage which your roommate caused if you chose the roommate. They can charge you for the full amount of rent if your roommate doesn't come up with their share. They can say NO Pets! even pets from your guests.
I can appreciate parents who want to help their kid and give them an advantage. It sounds like you need to be independent (financially speaking) from your parents. If your parents are trying to "help" you by financially giving you a break and have conditions to encourage you to make more responsible choices then that is their choice.
You are an adult and can make your own choices. Like these others, I have little compassion as you need to pay your own bills, accept responsibility for your own choices, and not have this victim mentality. A victim mentality often shows that you will blame others for your choices. It sounds as if you want the freedom but not the responsibility. Those two ideals are directly tied together. I have been a landlord for years and get rid of tenants who feel entitled to other peoples charity.
It would be best for you to find a new place, get your credit repaired, save up and rent with a different landlord. That may mean you move to an area which you may not like and pay more in rent. Greg is right, there are mom and pop landlords which will rent to low credit people but it may not be in a preferred area/home. Once you establish a good renting history and complete a year lease, ask for a reference from the landlord and use it find a better place and area. Parents do not count when I ask prospective tenants about their renting history. Cut the financial ties to your parents if you want more freedoms. Most of all be GRATEFUL that they are trying to help you and teach you responsibility.