POS Awesome Multiple User settings and Implementations

Hi @youssef … POS Awesome has really made the retail functions very easy to handle, however, I need some guidance on permissions and settings for a sales user of POS Awesome.
I have two stage transaction at my retail outlet :-
Stage 1) where orders are received and bill handed over to customer for payment
Stage 2) where bills are paid and items are handed over to the customer.

Queries: Using POS Awesome;
How will I disable the payments at stage 1
How will I transfer the invoice from stage 1 to stage 2?
How will I disallow 2nd stage to generate new invoices?
Is it possible in POSAwesome & how? Please guide.