I can try and answer some of OptiTron's questions:
The children do learn from the chief's lectures. The chief in question must be over 18 years old, and have a certain level of leadership. Then, once every 24 hours, drop the chief on a child and he will lecture, and all the kids will come running. When the chief is done, a little light will come over each kid's head, then the kid will run off. Check the skills bars, the kid will have a little skill in something.
There is no sound signal when collectibles appear, except when the chief points out a rare collectible, there is a noise then.
Lastly, the symbols above the rose bush are a recipe for an important potion. I can't guess what went wrong with your game. maybe some more expert player than myself knows that?
My comments about the game:

love these things:
Footprints in the sand
Running to get out of the rain
Building sand castles
The Roster of the Dead
The coral reef - gorgeous!
hand gestures
Playing in the puddles
Thunder and lightning
Children gathering herbs
comments like "Tofu sees Ariki"
seeing the doctor run to help a sick villager
kids gaining skill by listening to chief
coconut-head is gone!
lots of mushrooms and collectibles to gather, in dozens of places around the village

things I wish were different:
everytime I turn on an old game I haven't seen in a day or two, there are bodies laying around
still don't have an ancient elder
miss playing tag
would like to spend my zillion tech points on buying that last elusive collectible

overall, great job LDW. Love it.