Update time to my experiments with improving GPU temperatures and case airflow. So as a recap:

• I've noticed that my video card was hitting thermal limits on workloads that normally didn't in the last case it was in, a Silverstone FTZ-02
• After looking at the case and thinking of the airflow pattern, I came up to this conclusion:
  
  
  
  The idea was that the case fans on the top and rear would draw the hot air (marked red) up and out. But there wasn't much airflow going there. So I stuck a case fan on the video card to draw some air up. I also did see some improvement so I decided to pursue this route.
• The temporary solution looked like this:
  

Deciding to make this a more permanent and elegant solution, I ordered an L brackets meant for mounting case fans to something (https://www.amazon.com/Coolerguys-Mount-Stand-Bracket-Black/dp/B0195FW4LI). This would mount to the case itself through the rear fan so I could mount another case fan above the video card. I also decided to remove the shroud on my video card because I feel like the direction the air needs to go past the fans was constrained by it. The end result is this:

I also happened to be at Fry's and they had white LED versions of Corsair's AF120/AF140s, so why not? The only problem I found though is they need to run at a fixed RPM through my fan controller, otherwise the light pulses occasionally which I'm guessing is the fan controller "kicking" the motor and the LEDs are powered by the same power-in line as the motor.

So was it worth it? Well, I'll let the numbers speak for themselves. The workload I used to test this was https://na.finalfantasyxiv.com/benchmark/

Before the mod (probably, I forgot when I gathered this data)

After the mod

So basically:

• The GPU was able to sustain higher clock speeds for longer, indicated by the higher average clock speed.
• The average and maximum temperature dropped
• The GPU's performance was not limited by thermals. Power and VRel are expected to be hit.