In your pictures you have plugged the PCIEx1 Riser into the PCIEx16 slot.
Does that work??? I never thought of that.
Yes , that all 7 Riser is work .
Do you have plug power cable into USB Riser
I have two power type slot USB Riser,it must plugged power cable~
http://imgur.com/a/eIXIhI will have to try now for myself

The SATA powered riser would be dangerous for AMD rx as they can draw more power through the riser than a SATA cable can handle, no?
Sata powered risers are still better than using Molex to Sata converters. And as long as you can keep each cards power draw under 120W sata powered risers are safe.