What is a guardian’s liabiltiy for the actions of their charge?

I would hesitate to say that a "guardian" is never responsible for the physical violence of a ward.  In 30 years of practice, I have never seen anyone try to hold a guardian personally responsible for this.  Someone else on this service may have seen it.  Having said this, let me say a few general things about guardianships.

First, you used the word "guardian" so I assume you have been appointed by a court to serve as your cousin's guardian.  If this is not accurate, my answer probably does not apply to you.  If you are some special kind of representative appointed under the Social Security laws or your state's developmental disability laws, then those specific laws would apply.

Second, you did not say whether you are the guardian of your cousin's person, the guardian of his property, or both (a plenary guardian).  A guardian of the property is definitely not responsible for the ward's actions.  A guardian of the property only manages property, not people.

Third, if you are a formal guardian of the person for your cousin, your actions should be approved and monitored by the guardianship court.  In Florida, you must have specific orders granting you authority, you have to visit at least quarterly, and you have to file regular reports on the ward's needs and your actions.  This provides a great deal of protection for you.  It is difficult to blame you for someone else's actions (the ward) when you have fulfilled your legal duties and the court has approved them.

Fourth, in general, a person is only responsible for his or her own actions.  In the absence of specific and unusual circumstances, no one is responsible for someone else's actions.  Therefore, it serves both your interests and your cousin's interests to address your cousin's behavioral issues.  Seek the advice of professionals about how to address them, and follow their advice.  If professionals advise that you should move your cousin to a more secure or more specialized environment, and you have the ability to do so, you would be well served to follow their advice.  If you stay informed about your cousin's needs, address those needs in a reasonable way, and keep up with the legal requirements of your guardianship court, you should not be held responsible for your cousin's actions.  You should feel free to discuss this in more detail with the attorney who assisted in setting up the guardianship.

I acknowledge you for your willingness to assist your cousin and your generosity in serving as his guardian.  I know this is not easy and hope that my answer has provided some reassurance.