I'm sure the missing mode of operation is due to it being a vzw rom, not a generic one (mine is as well and hopefully a reg hack will appear
Actually - as mentioned, EV only will kill all calls (data only), 1x only in general may use more due to d/l speeds, BUT - if you are in a weak signal area, your phone will constantly hunt between EV and 1x and use a LOT of battery. I work in an old concrete type building and it kills my battery quickly... though the increase in signal with 1.41 and 1.43 has definitely helped.