Well, not to be a pooper, but let me try to answer some of those questions. .
The Recic doesnt stay on, because its not good for the AC system when run for extended periods. Running in recirc once the cab is cool causes high head pressures in the refrig system, which stresses joints and exchangers. I guess dodge's opinion is to try to minimize stress on the system to avoid failure.
As for the E-brake, it shouldnt be run in slippery conditions, like snow/ice. Again, guessing that dodge is taking the cautious route and not allowing the auto-enable to prevent any accidents/etc. Being that they sell more 2500/3500 models than 4500+ (which auto enable), and the 2500/3500 is more of a 'consumer' model than a commercial 4500+, the possibility of an accident caused by an auto-enable is pretty high, as is the lawsuit possibility. Dunno about the tow-haul angle. . I no longer use tow-haul as it really stresses my drivetrain with its excessive downshifting at inopportune times.
That said, I`d like to see auto e-brake enable in my 3500. . prolly wont see it tho. .
-j