There are many issues here. You need to consult with experienced business litigation attorneys. Use the Avvo search tool to find an attorney....

It depends on more details. If you were lawfully subpoenaed, you probably must go.

Contact the creditor or view the judgment and calculate the amount due adding the interest.

You may have a lawsuit against the sender of this email. Consult with experienced attorneys in the state where this occurred.

Courts can often be search online (or at the courthouse) to see if it is a real lawsuit.

Yes. Costs are recoverable in most cases.

When a company or a person violates a contract and will not make good, you may need to file a lawsuit.

If you caused it, yes you can be made to pay. Check with your condo owner’s insurance to see what they cover.

It depends on the details of the agreements and dismissal.

Yes you may have a case. Possibly, including for fraud.