How can we create a plan for free subscriptions that do not require billing information?

We have a feature called Cardless Free Trials you can use for this scenario. You can visit the plans configurations page and create a new plan. Directly below the timing for the trial you will see an option to require or not require billing information at signup for the subscription, simply set this to Do Not Require and you'll be able to add the subscription to accounts or allow customers to signup without needing any information being stored on the account.