We're not looking at handling the payments directly at the moment, as that could complicate things quite a bit (we have to store custom pricing for each merchant and each order etc).
It might be something we look at long-term, but not for now.
Customer handling would be a big help for marchants wannabes like us. Currently we only have the resource to put a lib into our app.
We are not sure how well printing would go
Is there a reason you only do rasters? I've believed that vector graphics is superior.
The printer has problems with the rendering?