You can sue them but the police will not prosecute.

You can sue him. If you can prove it was intentional, you may be able to receive a punitive damages judgment.

An attorney might be able to pick up the case from this point, depending on many factors.

Yes that may be negligence. Consult with experienced attorneys.

Report this to the FBI. They handle this sort of fraud.

If your insurance does not handle it correctly, it would be an insurance bad faith attorney.

Unfortunately some people do not know how to properly communicate. You may need to take extra steps to prevent overspray and loose balls.

It may be a scam. Whenever one is unsure, give no information, demand proof in writing (do not give your address or other information),...

If it was settled, and that can be proven, they are not entitled to payment.

You are probably uncollectible. When the learn this they might stop collections. If not, once you are no longer uncollectible, bankruptcy might be...