"Neduro and a few others seem to think it can do the TAT and some highway as long as you stay below 65 mph"
stick to tubes, don't take the word from others,,"seem to think," unacceptable.
As far as water goes, only place it is an issue would be Nevada and Black Dragon/Eagle and Cat Canyons in Utah.
I found the only place I needed water was in Black dragon Canyon, I drained the camel back but was with two other riders. I didn't have the bladder filled, but carried a 24oz water bottle on the side strap thingies on the Wolfman. The wolfman has those water bottle holders, I used them one for oil, chain lube, air filter oil and 24oz water bottle.
Most days the camel back alone will be plenty as there are places to fill up during the day. I used lunch stops to restock toilet paper too. If camping figure some sort of lunch stop which won't be hard to find. Our group ate out 90% of the time, so food isn't an issue, plus we usually enjoyed imported beer every night!!! It's good to have some food just in case or the evening meal at camp. Dehydrated stuff is small and not to bad to eat.
You're going later in the year so I suspect water will be less of an issue, except would want to fill the bladder up for night time cooking and camping for personal hygiene.
Really you need to get comfortable doing tire changes it will take 3-4 changes to get your technique down. A small can of WD40 for tire tube is quite helpful. You need someone to show you what to look out for as not to pinch a tube!!! Plus how to patch a tube.
I never went below 18 psi, and never had a flat and hit some pretty good stuff in Utah. 4mil tube front and 3mil rear.
a little item I forgot and was quite glad to have later was a bandana to cover my neck from the 4weeks in the sun.
Make sure your boots and seat are comfortable, I had few miles on a Corbin and it was pure hell for 4 of 5 weeks, boots wore blisters on my heels after much walking in Black Dragon Canyon. Even w/ band aids and mole skin it was painful...and nothing helped my ass!!!!