H Murphey is correct about the vibration. We just trailered our Hobie 18 Magnum from Buffalo NY to St. Petersburg, Fl. I did have straps going over the front and rear sections of the boat and they did vibrate. The rear one actually chafed to exhaustion because of the vibration and I had to cut it and retie it. On the way home, we'll go back to four corner tie downs. I had a nice set, but they rusted away. Maybe home depot will have a shorter set.
As far as trailering a boat, we have cradles in the front and a single roller in the back. We've never had any damage trailering. The only extra care we take is to make sure the wheel bearings are repacked before the trip; a task I do every time I put away the boat for the winter. Make sure you have covers on the bearings, so they don't spray grease all over.
Wyatt