Steve,
1) Main trail, roundtrip, "car-to-car".
2) Basically, I never go at a pace that I couldn't carry while breathing through my nose. With few exceptions when the terrain gets too steep or I want to move through an area quickly, I won't breathe through my mouth. This allows me to keep myself and my pace in check. Since I'm not straining, I'm burning mostly fat and don't need much. I think I used 2 liters going up, and filtered a liter at a small waterfall below Consultation Lake while I ate a McDonald's McMuffin on the way down. Other than that, I just had 2 gels and a few gummy bears.
3) New Alpinism talks in great and technical terms about what I described above, all in very to understand terms though. It's about how to build a huge aerobic base to support more specific training depending on what you're looking to do. Summary is to do most of your training in the aerobic zones and spend the other times developing strength. Simple techniques and exercises to develop endurance. One of the authors, Scott Johnston is an Olympic level coach and has climbed K2. Steve House climbed a new line on Nanga Parbat, alpine style, in 8 days. Check it out, it's well worth the price in my opinion.
Here's the basic premise. It's near the front of the book from another well known climber. Again, not looking to argue with anyone about what works or doesn't. This worked/works for me.
http://www.marktwight.com/blogs/discourse/85824260-no-free-lunch
