I have my TT insurance thru my Auto Policy ( Hartford AARP)for our 2014 Jayco Eagle. Premium is $110. per year. Thief within the trailer is cover under my Home Owners policy. The trailer in case of total total loss is prorated by the RV Blue Book. Collision or Personal Liability terms are the same as my auto coverage. No Towing is included because I did not purchase it (I have free towing for one year from Jayco).
When I compared Good Sam's policy and costs they mirrored my Hartford Policy, but the cost was 2 times higher.( they cover many items which were already part of my auto or home owners policies. Many of these RV Policies over lap many of the coverage's provided by your auto and home owners coverage.
Ask a lot of questions to the insurance carriers, I have outlined above. You will see there is over lap and a rider on your auto policy will give you good coverage. I was not impressed with the Good Sam insurance and the poor response to my many questions re coverage.
To get coverage to cover De lamination you would need to go to a extended warrant policy and I then, doubt if any extended policy would cover that. It like rust on your car, its not covered. If the delamination was caused by damage ect. the standard insurance (my Hartford policy) policy would cover that damage.
Good Luck it certainly gets interesting when you really drill down asking the insurance carriers EXACTLY what they cover.
G