1) I pace by using a combination of perceived effort and heart rate. I know that I can maintain a 155-158 for over 3 hours (85% of HRmax for me). Generally this means that I will be going 'easy' for the first hour and that a lot of folks will go past me. However past experience has shown that revenge is mine above treeline. Generally speaking, the faster you are, the closer you can get to your max. The opposite is also true.
For time based pacing, go to Matt's pace calculator at http://www.skyrunner.com/pace.htm and use that. If you are just starting, enter in your marathon time as your goal. If you are from lower elevations, add 30 minutes. You will then get splits to try and hit.
If you have never been on the trail, try this: Get a treadmill and set it to 15%. Find a steady pace you can run at for an hour that does not leave you exhausted at the end (just bored to death). Note your effort level and/or heart rate and try to maintain that during the race.
2) For wave 1, I go with a 20oz hand bottle. I refill it at the aid stations as needed. For folks out there longer (like all of wave 2), the camelback comes in handy not so much for the water but as a place to stash jackets, gloves, hats, food, etc. (yeah, you can wrap them up around your waist, but a camelback is just so much easier and makes getting stuff a lot faster.)
One note on the hand bottles: wide mouth bottles are really easy to refill at the aid stations. Narrow mouth ones or the little fuelbelt things are a pain in the ass and will result in most of the water hitting the trail when you go to refill it.