John, Sometimes I brine, sometimes I do not. I don't always brine a turkey before cooking it in the oven? that's not any different than doing it in the WSM, cept you are using charcoal for your heat source, and most likely some wood for extra flavor.
John,you should be okay. Yank it when it gets to 10* below done,and let it rest for 20 minutes. The holdover temps will finish cooking it and keep it from drying out. HTH