How about Tribes. If the island was split into 4 or even 5 areas (N,S,E,W and centre) then you could set up a tribe in each area and, when the villagers are far enough advanced, they could start "exploring". Once an explorer makes contact with another tribe they might start trading goods. Alternatively, you could start with one area only and the explorers could find suitable sites for expansion. Then you could send out settlers from the original tribe to make the new one. You wouldn't need to see the explorer until he/she found something. And you could also have the computer run the other tribes for a bit more of a challenge.

I also think it would be better if "parents" just cared for the children (teaching, cuddling, cleaning house & doing laundry) and only "went indoors" of their own accord with another designated parent. You could still connect villagers who weren't parents and create children but that would only happen when you controlled it. That way you don't get parents interferring with another villagers training all the time.

Also, if a mother wanted to gain a bit of experience while caring for a baby, maybe they could give the baby to an "elderly" villager for a while. When granny has had enough they just give it back.

I would also like to see doctors training at the hospital. Maybe doing research there like the scientists only gaining experience only.

Maybe as an overall thing you could have moral shown. If a child is particularly happy they might pick up collectibles on their own but if they are sad or grumpy they may not do anything you want them to. (Just like real children)