After killing the bandits and turning in that quest the King should have directed you to speak with the Commander, who is having a problem with a certain troll... once you've killed the troll, have a chat with the barman in the tavern who may mention some trouble north of town, where a captain has set up a tent as he is being overrun by witches in the valley below the farm (these quests open up in the 7th tab (Quest Journal) in the HQM from memory, they're invisible until triggered though). Completing the witch quests will open up a new branch featuring the dead queen, she and the priest will both have a story for you once you've taken care of the witches and their leader.
Hope these help a little. You don't have to do anything about the magic/tech/decoration etc questlines until after you finish the storyline quests if you don't want to (or even at all if you don't want to), but the rewards you get may help out with some of the tougher enemies...
Cheers.
This brings up an interesting point. Someone might want to try making a players guide for this pack. I'd hate to miss parts of it because I forgot to talk to one persion.