Relax and enjoy the trip
After reading all the posts; don't get too stressed out with all the possible things that could happen. Very few things will go wrong. We tow our H26 which weighs about 6000 lbs. with a Nissan Pathfinder and after a while you forget it's there. As for strapping down, you have good advice here, but make sure you have a safety chain with a lock on the bow of the boat. Since I have a cable on the bow eye, at the winch, I add a chain attached at a different place, the padeye on the bow above the rub rail that is used for the front mast shroud. That way I have two dfferent attach points.
You must find the best speed that results in the least amount of transmission shifting. As noted a self-installed trans cooler for less than $90 is cheap insurance, but it is constant shifting up and down a gear that causes the heat, not prolonged driving. We have found that speed to be 56-57 miles per hour. Yes, I know it seems slow but at a higher speed the trans is shifting on every incline. At the lower speed it can make a lot of grades without shifting.
Get a load equalizing hitch or lifting airbags from AirLift corp. (these are around $85)
http://www.airliftcompany.com/ Measure the height of the hitch on the truck. Then put the trailer on it. You will see how much the truck drops. How ever you do it, you want it back to the original height. I use arbags because I have hydraulic surge brakes which must move forward and back at the hitch and a load equalizing hitch doesn't allow for that.
Don't go crazy trying to get 15% on the hitch but do get as much as you can. As I said we are at close to 6000 lbs and I can only get around 400 to 450 lbs on the hitch. This has never been a problem.
As stated, lots of bungees and we also have a 2x4 with a notch that sits on the cabin top mast base and supports the middle of the mast for less flexing.
For the most part, with very, very, few exceptions, other drivers don't give much grief. Signal way in advance for lane changing, a talking car gps is invaluable for alerting you ahead of time. You must get one to reduce the stress if you don't have one. Remember that you are very long when changing lanes because you WILL forget. Truckers will always be helpful allowing you in and giving you room.
Have fun! Make it an adventure. Pretend you're young and carefree!
John