Possibility to edit payments would be amazing. It would nicely suplement the feature of automatically marking an invoice as paid. Or even better, if would be great if it would ask about the payment date when marking invoice as paid. This would allow to upload data retrospectively.
I'm not sure about what do you exactly mean with edit payments but you can mark an invoice as paid from the More Actions button, in the invoice details page.
What I really mean was the possibility of changing/influencing the day when the payment was made (when marking invoice as paid).
This would allow to "catch up" and create invoices retrospectively and mark them with payment date when they have been actually paid - which could have been in the past.