Wesley,
A few things come to mind regarding your post.
First, if you are able to have a base weight of 12 lbs. AND have the extra Philmont stuff in your pack you will do great. I think I had 12.5 lbs. base due to carrying a pot and some rope. I usually carry about 9+ lbs. as a base.
Second, I felt the same way about the dining fly BEFORE I went to Philmont. After using it at Philmont I am an adherent. No, I am not using one in the Sierras, however, we found the dining fly extremely useful and smart while on our trek. We had numerous times when we arrived in camp during a rain storm. All we had to do is set up the fly, and all get under it. It was some of the best time spent on the trip, because, as you know, young scouts can be quite funny. Having 12 of us under the tarp can bring tears to your eyes. And that's not just from laughing.
Having the fly also allowed us to cook dinner during these storms. Since they make you cook together you really can't get in your tent and cook in the vestibule all on your own. We could prepare dinner and wait for the opportune time to set up our tents as weather permitted.
We took a Silnylon tarp that weighed a lot less than Philmont issue. Also, the 6 qt. pot is a good choice. You can easily heat enough water for the troop. We did not cook in the pot. Each kid just re-hydrated their own food in their own plastic cup and drank the cup clean. Very little to sump.
As far a pack weight, just go to the scale at the check in area. Watch the kids and adults that are putting their packs on the scales. 40, 45, 50, 55 and I even saw a 62 lb. pack. It was good sport for our kids to put their packs on the scale again after seeing a 57 lb. pack. Some of our (punk) kids would say something like "Oh, no!" and then people would look over assuming they were going to say they had a heavy pack. Instead, they would say, "it's 25 lbs.!" People would just shake their heads. That's real light at Philmont.
Enjoy
