The lighter you make your base pack weight the more you reduce your caloric intake needs. Which in turn reduces the amount of food and fuel needed. Which in turn means you don't need as heavy duty a boot. There is a pattern going on here and that pattern can work in the opposite direction of increasing weight as well
This is exactly right. The more you take, the more you have to take. And, the less you take, the less you have to take. Sounds like some circular reasoning, but if your base weight is 10 or 12 pounds, you could wear trail running shoes and you can cover more ground in a day. If you take more (and heavier) stuff it will slow you down. Maybe you could reach the next town to resupply in 6 days with your 42 pound pack and hiking boots. But if you cut your pack weight to 20 lbs and wear running shoes you could reach that town in 5 days. Since you can now get there in 5 days you can cut a day's worth of food and water from your pack and maybe get there in 4 days...
Same with carrying water to the next water stop. With a 20lb pack you might be able to "camel up" and reach next water without carrying any. With a heavier pack you might have to carry a litre or two just to make it to the next water stop.
Here are a couple of sites from guys who have cut weight. They are as detailed about hiking as guys here are about their LandCruisers. If you want to thru hike, you WILL be shaving ounces. Do it before you begin, or you will do it on the trail.
Onestep's Ultralight Backpacking Resource
Joe's Ultralight Backpacking
A site about technique complete with a gear lists and reviews of many items:
BackpackingLight.com -- Home Page
Here is one lightweight vendor, just to show what is possible, there are others...
Gossamer Gear - Ultralight backpacking and hiking gear
IMO dragonfly and whisperlight stoves are still too heavy for a thru hike. If you take one of these stoves, you need fuel, which means you also need a metal container to carry it in. (the more you have, the more you have to have) Try an esbit stove or alcohol stove. These can be 4oz to under 1 oz, and the fuel is dry, or can be carried in a plastic bottle. YMMV Be sure to practice.
Here are a couple rules I go by.
1. Don't pack any more clothing than you can wear at one time.
(I still take an extra pair of socks for sleeping)
2. Don't carry more than one item that serves the same function.
3. Carry the lightest item possible for each function.