About the "based off of appliances" thing. As of now, there are no Pokemon that are actually house appliances. Just one Pokemon that can possess them, yet for some reason has to pop out over Wi-Fi battles...?
Ants. There are plenty of bees/maybe wasps, butterflies - how about the good old, hardworking ant?
Plenty of dual types that haven't been explored yet, like Grass/Ghost among others previously mentioned in this thread.
Click picture for personality survey, from "The Cave of Dragonflies."