Business / Residential address indifference? And other new advice

In Account Info, there’s a link to enter your Business Address, but on entering the form, it shoes ‘Primary Contact’ and states ‘Residential Address’ as opposed to ‘Business Address’.

Obviously, I know the difference, but why does it say residential when I select business?

Summary: Do I enter my registered office address or my residential address?

Furthermore, as a new seller, is there anything you would recommend completing apart from the basic fields?

Many Thanks.