Have you tried doing one with lump and just a little wood?
Chicken does not have a strong flavor on it'w own and can be overpowered by smoke.
If it tastes bitter you used too much smoke, or too strong a wood or not enough draft.
Smoke can get stale in the chamber, especially in an offset. If the smoke leaving the chimney looks thick or dark increase the airflow. You might also try biulding a smaller fire which will let you keep the heat down AND add more draft.
If it just looks burnt and tastes OK it might be the sugar. Try using raw, or turbinado sugar. Mexican cone (not cane) sugar also has a higher burning point.
As for the kiddies try just salt and pepper and oil on the outside and a mild paste type rub containig honey, a little butter, a little cinnamon and allspice placed under the skin. It won't burn there. Also try an underskin paste rub contaning fruit of some sort.
Grind up raisins, shallots, pecans or walnuts, s&p, thyme, and butter into a smooth paste and rub under the skin.
These are some of the things we've tried to make BCC more kid friendly.
With and offset you have enough room to do at least 4 at a time. Make a mess and play!