It should still be T-Zones capable (you'll need to enter the correct T-Mo data settings in connection settings if those got wiped out in the unlock and flashing). As for MyFaves, if it's the WinMo 6.1 upgrade for the T-Mo Dash that you flashed, it shouldn't have lost MyFaves. If it was a generic ROM from XDA-Devs or some such place, and the MyFaves software wasn't in the ROM image, I'd *think* the feature would still work, though you wouldn't be able to make any MyFaves changes on the phone itself. It doesn't matter if the phone is unlocked as long as it's running the T-Mobile Dash factory ROM image.
-------------------- Lisa Gade Editor in Chief, MobileTechReview