Hanging things on the walls

Its your trailer, you can put holes in the walls if you want. The walls are thin lauan plywood, don't expect them to hold anything very heavy, and the walls are only 1 inch thick so don't use fasteners longer than that. There is only foam in there so no benefit for the screws to engage more than the quarter inch lauan anyway. The sticky things will probably fall off qucikly, trailers are more subject to temp and humidity changes that houses so the adhesive will be more likely to have problems. Also, consider that anything you hang on the wall will effectively be twice as heavy as the same item will be at home, due to roadway bump loads.