I mean I don't want to eat off of dishes with bacteria on them but regardless there's no arguing that a dishwasher uses less water than handwashing. It's kind of hard to beat 3-4 gallons of total usage for both rinsing and washing an entire double-sinkload of dishes.

Absolutely not if you do a half decent job at washing them. Sanitary is a pipe dream anyway. The cabinet they're going in isn't sanitary. The air in the kitchen is full of fecal coliform bacteria. People don't wash their hands before they handle plates.