These questions should be directed to an attorney.  However, my unofficial and not to be relied upon comments are as follows:

If you issued reports as an LLC then stopping the business does not create personal liability.  Terminating the LLC may even be a good idea-check with an attorney.

A tail policy should cover the time period for the statute of limitations on negligence claims-again check with an attorney.  You may not need one if you have operated as an LLC.

 You really also need to check with an accountant to close out the tax side.