We have done integration of shopify with openerp 7.
1. We can import Orders & customers database from Shopify to openerp 7.
2. We can import orders as sale orders in openerp 7 but in this we have created delivery orders in openerp 7 which are orders at Shopify.
3. We have created scheduar for export product quantity from openerp 7 to Shopify. Whatever product quantity at openerp will be updated on shopify at schedular time and it is based on product default code in openerp & sku on shopify.