When searching through your subscription signups, There needs to be a search field entry that allows you to segment which accounts have a card on file and which do not. The benefit is that I can request it from those people instead of going into each one individiually.

Additionally, some have cards on file but the card is not associated to the subscription yet.. A place to view this as well as I keep getting unpaid email from customers not realising the card is not associated.

There is no way of knowing!

A subscription is supposed to be automatic payments. How can this not be the most important component to manage all customers.