hi Rachel,
(1) yes, it is a one-time fee per account. You can use it on as many boards you want.
(2) currently the webshop only supports PayPal, but you can easily transfer money from any CC to PayPal
(3) our current offerings can be found on Downloads Archive - Excellent Team. A new one will be added soon which allows for moving items between groups based on status change, see also: Status Done PER GROUP - automation to move row to next group - #4 by basdebruin
(A) Currently no plans for integration with Peachtree/Sage, but I am happy to look into this.
(B) sorry, no focus on the mobile app at this moment
(C) interesting idea, have to look into that
(4) Not entirely sure what you mean by this