I smoke my birds at 225* until 140* temp, then bump the grill up to 400* or a little less to crisp the skin until the meat probes at 165*. I don't use a water pan as that seems to keep the skin rubbery. Everything I read says smoke 30 minutes per pound but mine seem to be done sooner.
One of the best turkeys I've done was at 350-375* just like in an oven. It wasn't as smokey as I like but was moist and tender.
I smoke at 225 on my MB with a 13lb turkey and that usually takes 7.5 hours. Drip pan below to catch everything and I do not put water in it.
Regarding your question on the water pan, it keeps meats moist (creating humidity) by stabilizing the internal smoker temp, but with a turkey or chicken it will not allow for the skin to get nice and crispy!
After brining overnight, I smoke mine at 275 (spatchcocked), and it usually takes 20 minutes per pound or so. I also baste the skin with melted compound butter (the compound butter is made from butter and the rub I use) every 30 minutes. Ends up with a pretty crispy skin, a nice amount of smoke flavor and super juicy.
did a turkey breast bone in.
Brined 8hrs (brown sugar, salt, pepper, hot sauce, and wostershire)
225 to start until internal temp of 140,
raised temp to 285 until 160 internal then pulled it,
total cook time about 3.5 hrs.
My Wife, my toughest critic, loved it,
texture and moisture,
used a water pan, so crispy skin did not form