While the idea of a no hatred generator build is interesting, I don't know how useful it will be. With the first build, your only real slow / damage dealer is Rapid Fire. Every time you someone gets close you have to run away to create separation somehow. The slow from the last Rapid Fire doesn't last long so that isn't going to help much. If you lay a caltrops or use Smoke Screen, that costs a lot of your discipline. You're going to be completely addicted to and dependent on discipline in this build and I really don't think you're going to be able to keep it up all the time. It's your only escape AND your only way to really generate hatred, that's not a good thing. Like I mentioned before, you're going to be constantly moving to avoid mobs and restarting your Rapid Fire channel for another 20 hatred start-up cost. This is really going to kill your single target dps. In entirely AoE situations you are probably fine with multishot because it gives discipline back, but single target is going to kill you. In fact, Hungering Arrow runed with Devouring Arrow has a higher damage output than your Rapid Fire - not to mention if you actually put a spell like Impale in the build. So even if you can keep up your hatred, you're going to have sub-optimal damage. It doesn't seem like the risk in going for this hit-or-miss build is worth the reward you get.
I don't find either build to be any more dependent on discipline than any other -- lots of folks will be caltroping and vaulting around. Smoke Screen, sure, is a bit costly, but is meant to be used in those AOE situations where it can be used in perpetuity. The second build takes just about every discipline-regen and cost reduction that it can get its hands on. With anything, we'll have to see how it plays in practice.
The second build also drops the initial cost of Rapid Fire (to below that of base regen + bat). Assuming your "first second" of rapid fire comes at that price, as opposed to Impales 25, it should be easy to keep it moving. Not to mention that with the removal of Mark of Death in the second build, Rapid Fire will still be just barely negative hatred per second (2 or 3), letting you crank on the juice where Impale might have run dry.
In addition, Rapid Fire plays a key role with Night Stalker. All the business about Rapid Fire having a reduced rate of "on-hit" effects aside, it will still offer a smoother return of discipline than a few imaples that may or may not crit.
Truth be told, I'm not even in Beta, so this is all just back-of-the-envelope building, we'll have to try it out to see what it can do. See you on May 15.