Consult a doctor. Report this to the health department. If you are injured, see a lawyer.

You can’t. While this was unkind, it would not provide a lawsuit.

If you can prove these allegations, you would have a very good case. Consult with experienced attorneys in the area where this occurred.

It depends on the precise language of the agreement

For what you describe, generally the 2 year statute of limitations would apply.

Communications between an attorney and client are privilege and would only be admissible in a dispute between the attorney and the client or if the...

Yes, if such evidence is otherwise admissible and relevant.

This may be the form: https://www.courts.ca.gov/documents/mc030.pdf

You can provide a timely notice to appear (or a subpoena-but a subpoena is not necessary for a party) and simply call the person to testify. If...

You need to to research the sanctions motion very carefully as they have many detailed requirements and there are risks if you lose the motion.