No. An employee, whether current or former, cannot use your medical record without your consent.
A former employee is a non employee. You can discuss what you want.
A former employee is a person who used to work for the company but no longer do. This includes those that were let go or that quit on their own.
I would imagine that you are wondering if you can be sued for slander if you speak critically of a former employee. Generally speaking, it is legal to speak the truth. If you were planning to tell lies about your former employee, that could get you into trouble.
yes
How would you describe the quantity and quality of output generated by the former employee
It depends on what she or he said. When a Manager or Supervisor calls your former employee for a reference, they are suppose to ask your former employee will you hire this person again, your former employee only suppose to say Yes or No.
No, they cannot. It's purely illegal. Contact the EEOC and they will do an investigation that may get you your job back, either way they will do something about it.
no
A current employee is still employed by that particular employer; a former employee is not.
yes
ADP pension information for former employee 121927
A former employee is not allowed to destroy company e-mails. However, an outraged former employer, if having knowledge of the company e-mail system, can possibly create havoc by destroying the company's e-mails.