It appears that WoW's engine isn't a fan of WOW TBC Gold when the GPU is able to throttle for my configuration. Even though my CPU wasn't sweating, I could see the flickering when my GPU was running at its maximum. The flickering would be aggravated by additional add-ons.
My in-game FPS limit was set at 60. It made gaming more enjoyable. It's pretty annoying since after a few minutes of playing at a higher refresh rate it is evident that you are getting back to 60 but it's still better than the flickering that I had to deal with.
So after changing my settings and setting my framerate down to 60, I experienced a good amount of flickering. This is what I stated in my earlier post. While I initially thought it was the fault of my GPU some part of me thought it was my GPU that caused the issue. My GPU will not be able to handle other games. It's the right time to upgrade my GPU. I'll need another. (I was planning to upgrade my GPU, but ...) But I think the GPU is fine. There aren't any issues with the hardware.
However, I believe that my issue stems from buy WOW TBC Classic Gold the fact that my version Windows 10 does not have the latest DWM, Desktop Window Manager or refresh rate code. This means that when I play WoW on my primary display needed be synchronized to the rate that my GPU was able to achieve, which is usually not at 144 FPS, it could eventually encounter an issue. My second monitor worked perfectly however it was set at 144hz. The DWM could cause an intermittent flickering and would then stop the frames on my primary monitor.