You dont need billing permission for your app if you are going to include ADS only.
When you want to make a not free app, you are gonna need to register as merchant account.
I have not created a merchant account yet because my country is not allowed to create merchant accounts, but I have read a lot about it and you can register yourself as merchant account without having to create an actual business. Google just needs an address and billing information such as a bank account number, that is necessary so Google knows where to send the payments. But those could be your personal address and personal bank account.