working with promo codes

Hi,

I think you could do that with HikaMarket Multivendor:
www.hikashop.com/hikamarket-multi-vendor.html
Each promo code owner could be setup as a vendor.
And in the coupon settings in HikaShop, you can configure the coupon to be assigned to a specific vendor so that when an order is created with that coupon, the order is linked to the vendor.
Then, you can also provide access to the vendor control panel on the frontend, with access levels to fine tune which area is accessible and which is not. So you can provide access to vendors to their orders. Also, vendors will be notified of created orders linked to them with an email.

So, it seems that it will meet all the needs you raised in your message.