Relay for stripe plus twitter oddities


We are testing relay from Stripe that works with Twitter.The basic scheme is nice and works but a deeper look shows:
1.No quantity appears in the buy ‘form’ .So u r limited to q= 1 .That covers only a little niche of processes.
2.No test products can be used ( test means products from the Test Sandbox from Stripe ,so u test u pay .
3.U cant add an extra param to the order scheme :so if u have some data besides the typical delivery data, you are lost.In our case a customer must add an account number and a given customer can have more than 1 account ( 2 houses,1 cabin,etc ) and order for each of it.
Any help & comment welcome