how to use Profile information for payments
It sounds like you're using a custom module with instructions that run counter to the Authorize.Net instructions. Is that what you mean by customer_profile_type_ui? I assume that isn't part of the core Commerce Customer module, so a link would be helpful, but honestly it looks like you've already answered your own question.

I don't really get why you'd disable the core Billing information checkout pane for having insufficient fields. If you add a field to your billing customer profile type, it will show up in the checkout form. What else would you need to do besides that?