1. I like to use a battery.
2. I like the way it is now, though you could maybe use micro USB instead. Then I would be able to use a phone charger as an AC/DC adapter if I want to.
3. Color is not so important, black is O.K.
4. The two probes as it is now is fine.
5. I think the waterproof probes should be standard, with the option to order the high temperature probes, either instead of or in addition to the waterproof probes.
6. I think the interface needs more work. I would definitely like to see an option for two large dials, a way to tell at a glance if you are still connected, and the ability to set an alarm so that if I'm using it to monitor an overnight cook, and something goes wrong, I might hear the alarm and wake up.