Mopping: while it won't detract from the end flavor result it will add time to the cook in terms of heat loss/recovery. Your smoker is designed to maintain maximum moisture.
Separating point& flat: You're probably best off learning the ropes cooking a packer whole. A number of competition cooks including Fast Eddy will cook flats and points apart..mainly to increase the bark on the burnt ends used for turn in boxes.
Injecting/dry flat. The point has at least 2x the internal fat vs a flat...hence it's not as dry. There's a few tricks to keeping the flat from drying out...
1. Injecting the flat. ButcherBBQ makes a powder many comp teams use. It's named Brisket Injection. The phosphates in the powder help maintain moisture.
2. Foiling (Texas Crutch) Once the flat reaches an internal temp of 165, foil it tightly and continue to smoke till it's done. Once done, wrap in a towel and place the meat in an insulated cooler. It will stay hot for at least 2-3 hrs and the juices settle.
Chicken: Quarters are a good starting point. Brining will add flavor and moisture. Smokin' Okie brining 101 can be found
HERE Be sure to read his other 101's. IMHO chicken is best smoked at a higher temp...helps to cut back on rubbery skin. There's endless techniques folks use to cook quarters and thighs but that's a subject for another day.
Best of luck to ya. Holler back with any questions...we're here to help