A cook a good idea and the less trained cooks could give our little sims food poisoning!
How about the retired having camp fires for the little ones roasting marshmallows and telling stories...or/and musicians they could start by gathering wood and things ..then carving and finally lean to play. They could be used to entertain, lead a attack of bugs away from crops and so on.
The idea of trades between villages would be great to, villages would have to exist off each other and the explorers would have to make the trades the sim would be gone for a set amount of time.
I like hospitals also and you could have random injuries like "the builder fell of the ladder he will be out of commission for (enter time) in the hospital.
Maybe if LDW does make expansions all of us could help by submitting art for the project or whatever we do that might help cause idea's and such take time and money. Helping with our own game would be cool.

It really is endless and if done well it is a good investment millions of players play games with expansions.