Fighting Drag, I've had this kind of runaway ideas all my life, and it wasn't until I got into my 50s that I was able to harness some of these ideas into useful reality. Nothing wrong with being young, and nothing wrong with ideas! -- but what you are proposing does not sound realistic.
First, as just mentioned above, you need to learn -- deeply learn and comprehend -- the Mutant Vehicle rules.
Then comes the "wrapping", which will completely hide the base vehicle from all angles, and at the same time create a good-looking pirate ship -- and sturdy enough for the wind storms, and road travel. This could easily take a month, with two men working full time. Many months, working weekends.
And to farm this out among different builders around the country -- just ain'tent gornar heppn.
Your idea requires a minimum of two vehicles, so I suggest you continue as you are doing, here on ePlaya, to recruit an "adversary". Each would then build his own pirate ship, and drive or trailer those to the Playa in August. This assuming both are invited to participate, and then you still have to pass inspection on site.
That minivan on eBay has a $4.500,- "Buy It Now" price tag on it. That's for just one ingredient of the project. Can you play in this league? I'm very happy if you can, but I remember biting over more than I could chew many a time myself -- still do.
Calm yourself down a little, and consider the project from the point of What Is Actually Doable. Most likely, the Realistic Thing To Do is to build something much simpler for your first Burn.
Pedal vehicles do not require licensing. I've had a great time with my two pedal vehicles, including letting other people "drive" them, which is seldom a good idea with a motorized MV.
How about a pedal vehicle with a teddy cannon, and then ask people if they would like to try to catch it before it hits the ground.
Here is a "ship" I built a few years ago for a Kinetic Sculpture Race. It is a pedal vehicle -- the same one as in my avatar. I just took the body off and slapped two sheets of paneling on it. Most lumber yards have this paneling that looks very much like a wood-plank boat. With a pedal vehicle, a two-dimentional "ship" would be OK.