The Payments Object - Couple Qs

Hello, I had a few questions about the payments object.

When I built my app I was using the stripe integration but my client decided to use authorize.net. So now I send users off site to process that and then I send all the info back to knack. I am still using the payments object to collect that info via the API in case at some point in the future they want to accept stripe or paypal.

My first issue is that when I was first setting it up I accidentally added connections to the payments table in places that didn’t need it. It seems there is no way to remove these connections?

My bigger issue is that sometimes Customer Service would like to manually add orders, including the payment. This just involves entering the amount and the transaction ID from authorize that they have done outside of knack. Is there no way to add new records to that payments object other than the API? Looks like the documentation says no, but I just wanted to double check before doing it via the API.

Thank you,
Lori