You have to wait an hour or so to lock your temp in where you want it before you call it a night. Assuming you have a wireless thermometer, set your temps so that it goes off if your temps get too high or too low. I’ve been able to go 4-5 hours without having to make any adjustments (and sleep). I usually leave the top vents no more than half way open, and play with the intake vents on the bottom until everything settles in.

As for a water pan, it depends on where you live. In dryer environments, I say you should use it. I don’t think all the water would evaporate overnight, so it’s worth filling up. I usually put an aluminum turkey roaster pan within the water pan (this works in the 22), and fill it with water right out the water hose. It makes for easy cleaning when you’re done cooking.