Hi wert!

You villagers reach their max population at 90 (although with twins or triplets you can actually get 92) so once the three huts are built, no more huts.

Your villagers will continue to thrive after you solve all of the puzzles are solved but you need to look in on them from time to time at least. Island events still happen after you complete the puzzles so loss of food, or diesease, or other major events that your villagers still need you for could pop up.

But they're also a hoot to watch!

Most of us started additional games after completing our first trying different tactics and every game plays out differently. SO you may want to try that!