You should not allow someone to use your home for a restroom when you are not there, and then blame the dog. That one, I just can't blame the dog for. If you give people the key to your house, and let them in whenever, the dog with a problem should be securely crated or kenneled.
The other incidents may be different though. If you care about this dog and she is good with you, then you will crate or kennel her when you have visitors, or you will not have visitors.
The dog is yours. It is up to you to put her down, or manage her so that she does not get the opportunity to sink her fangs into anyone else.
One bite and you know that your dog will bite under certain circumstances, and all subsequent bites are on the owner. Allowing your dog to bite multiple people will eventually bite you in your pocketbook as well as in your heart. If you continue as you are, you are going to get sued, your dog will be put down -- no longer your choice, their choice, and you may have to deal with know that you cause disfiguring injury or even death of someone, maybe someone you care about a lot.
I am not saying that you should put your dog down. I am saying that you need to figure out how to manage your dog before something tragic happens. You need to crate or kennel your dog when strangers are around. You need to change your leadership style. You need to get a trainer/behaviorist on board. Maybe you need to euthanize your dog. If you cannot manage the dog properly, then euthanize the dog.
But buying a dog breed known for protection/guarding behavior and blaming the dog for protecting your home from a non-resident when you were not there, well, that seems a bit unfair.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC