What advantages do islands offer to people choosing a site for a settlement

Advantages of settling on an island include access to harbors which facilitated exchange and commerce. This attracted many people which sparked urbanization. They were also served by availability of rich soils for agriculture which facilitated food production to sustain large populations.

the effect of the ming leaders banning ships with more than two masts was that there was no further construction of ships masts, because there was a surplus. ming emperors disallowed foreign exploration