Can I restrict download when my macbook is being hot spotted?

Solution 1:

Little Snitch

Little Snitch has profiles that you can switch to which can contain custom network rules.

For example, you can create one profile that is bound to your home network that allows all incoming/outgoing connections for all applications, then create a second profile that allows all connections for Safari, but blocks all connections from other apps.

Alternatively, you can request that applications ask for connection when not connected to your home network.

These profiles can be switched through the menu bar icon, or automatically upon joining a certain network.