Yes.
Being disabled does not put one above the law. Anyone can be sued.
Yes, you can.
other person get sued
Yes, they can be sued. Its law.
No. They can only go after the assets of the person that is being sued. If you have a joint account with that person that is part of the other person's assets. Any account that is just in your name is safe as you are not the person being sued.
Most courts, that I have heard of, need a written "contract" with the person taking out the loan signature.
Yes.
Yes, just like any person or professional he can be sued.
They are the defendant. The person suing them is the plaintiff.
no
Different terminology can apply in different jurisdictions. However, the person being sued is probably most frequently called the "Defendant". In some cases the term "Respondent" is used.
Corporations may be sued for failing to control, or monitor, or properly supervise, the actions of its employees, however corporate entities cannot be directly sued for a "person-on-person" offense such as aggravated battery.