The way I see it, the GPU and motherboard are very close back-to-back with no airflow between them. Won't that cause problems? The back of my 750Ti gets pretty toasty, and that isn't even a very powerful card.
I think "airflow" isnt a real thing in there. With no case fans, i I hope the is a good cutout for the graphics card on the side. All hot air from GPU and CPU will leave to the top (if the card hasnt a radial fan) and thats all. Should be enough space for a good topflow CPU cooler tho.