The resort owner is required by law to register their quests with the police on the first day of arrival. This has been needed for years. Complain with the idiots at the resort instead of the people at immigration.
I don't think any insurance company would refund you the money you spend on restoring. Your emotional loss and the money you spend on it won't be covered from my point of view.
No experience but it seems a very complicated option as there is no direct train.
How would you get your stuff on the train in CM? How would you move it to another train in BKK? How would you move it to your place in Phuket?