I know exactly what you mean Eugene.
Quickly I am realizing that the Viart teams market plan is to give you a slightly "crippled" but potentially brilliant cart software. Then charge customers for "fixes" and "modifications" that they already have "up their sleeve" ready to go.
Having said that, in the Manual, the Edit Orders feature is included and does allow the changing of qty ordered and price, but I cant do what I want to do, ie change the postage cost, and the discount does not seem to be effect the total.
But if we pool our resources, the "fixes" become cost effective.