Simplest way to achieve this is to edit the Server Validations Server behavior and add required validation for the three additional fields.
Go to Window -> Server behaviors.
double click the Server validation server behavior.
From the validation type, select Required / not Blank / Selection made validation.
Click the lightning bolt next to server variable and select the Address form element, then click the plus button to add it to the list of validations.
repeat for the other elements that you wish to add, then click ok.