You can tell them to piss off but they can beat and/or kill you and get away with it so words arent really gonna have much stopping power in this case.

We live in a society where might = right. If you have the firepower or other means to stop them from entering your private space then you have the right to do so. 

You don’t really have the right to shoot anybody. (Depends on the state) But then you’d be accused of shooting a federal officer. Do you realy want that?

Yes i would absolutely prefer to die on my feet then live on my knees. 

Most states, even ones with a duty to retreat, will still allow for using lethal force against home invaders, and even if not good luck finding a jury to convict someone on that kind of an incident.