Your PSU and GPU actually blow the other way so the bottom intake fan is supplying the GPU with fresh air, which is good, and the PSU sucks air in from the bottom and it escapes out the back. You have too many exhausts compared to intakes though. Is there no room for fans on the front of the case? A better setup might be to move the 2 top fans to the front, this will create more of a flow of air from front to back and sweep out the hot air, rather than turbulently coming in from all sides.
This may also help reduce dust build up if the front panel is filtered. With more exhausts than intakes this creates negative pressure where it sucks air into the case through any possible ventilation - and all this air coming in from every nook and cranny is completely unfiltered.
If you have more intakes than exhaust this creates positive pressure where all the air coming in is coming from the same source and can therefore be filtered easily to keep dust out.