Hmm, that sounds fun. Room for a passenger? I don't mind squeezing into a suitcase or something.....
Not sure if this would fit into your timescale or not, but while you're in Arizona, I'd recommend heading south from the Grand Canyon, and stopping at Sedona.
The airport is mainly used by local aircraft taking tourists over the mountains. Its short runway is on an incline, so you'll be landing uphill and taking off downhill unless the wind is very strong. (The wind was very strong when I was there, but blowing straight across the runway - I gather this is quite common.)
Speak to a company called Pink Jeep Tours. They have some excellent professional off-road drivers who really know their stuff. And they'll collect you from the airport, too.
If you schedule is too tight to stop there, I'd still recomend flying south and making a small detour - there is some beautiful scenery down there.
I don't recall anyone asking me for my age when I booked hotel rooms, but a credit card will be very handy. And of course you know that you won't be able to drink alcohol - but if you're flying every day, you probably wouldn't want to anyway.
Have fun! And if you manage to get on-line, you could always start a thread with a diary of your adventure as you go! (It would probably fit in better in Private Flying than Wannabes.)
FFF
------------------