I hate fat-fingers.... I was finishing #4 and erased it all.... Try #2
Background - Ive been a contingent advisor for our last 4 Council contingents. Advice is worth what you pay for it
1. Yes, Philmont has tents. Last year they started replacing the non-free-standing tents with a custom design from MSR. It's very similar to the MSR Nook 2. By 2014, all should be replaced. Tents are checked out with the rest of your crew gear and returned the same way. Tents are inspected on check-out and check-in. Your tent looks good. There are pros and cons of your own vs Philmont's. The only other "personal" gear available is a pack rental ($18 last year).
2. We advise a 20-30 degree bag. Even late in the season it can get cold. It's also easier to open up a too-hot bag than to wish for more insulation. Murphy is on Philmont's permanent staff.
3. Our crews have had a mix of inflatable, self-inflating, and closed-cell. All worked well. Just be sure to pack the inflatable and self-inflating INSIDE the pack. Closed-cell can be strapped to the outside if need be.
4. Boots. If he's happy with the Keens, go with them. Quality boots should last more than 2 years. My Vasques made 4 treks before I blew them out on the Appalachian Trail (at over 1200 miles of total hiking). I'm currently wearing Vasque hiking shoes - not boots. There's no way to know if they'll make it except for checking them out for deterioration on a regular basis. If his feet grow, I'd recommend getting boots no later than March, 2014. Wear them everywhere until the trek. He'll do fine. In addition, a pair of camp shoes feel good once boots are off for the day. They also provide a backup in case of a boot problem.
The water thing is variable. The best solution is planning. For example, the first trail day is generally only 2-5 miles with water available at the campsite or nearby. There's no need to carry more that 2-3 liters to get to camp. Other days will have other requirements. This is part of crew planning - checking for water and destination on the night before each day's hike. The least I carried on our last trek was 2 liters (starting in the morning). The most was 5 liters (going into a dry camp).
Lots of other stuff to consider, but I'm about typed out. Philmont Forum
is another source of advice. Feel free to email if you wish - email@example.com
I hope he enjoys the trek!