That code is for speeding - too fast for conditions.
CHP does not always issue a citation, this is just the officer's observation at the scene.
Insurance companies do not always accept responsibility, even when it should.
He can be traced. You can also serve by publication if certain conditions are met and the court allows it. There is also a form available from the Postal Service that will provide a physical address for a PO Box registrant.
There is not enough information given to accurately answer this question. Much depends upon the amount or percentage of income, growth in value and the timing of that, and the marriage. Consult a family law attorney.
You should have an attorney prepare the release and provide the full facts as to the reason you are paying for the property damage, if caused an accident for example, you will want a release from any injury claims as well.