Well, I finally got the pump out of the computer and have been testing. I made a small closed loop on the in and out ports and ran just pure DI water for testing. What I found is exactly what I thought the problem was, the impeller simply stops spinning after about 2-5 seconds from initial power on. With the clear Bitspower pump top, you can see it start to spin for about 2 seconds, then slow down until coming to a near stop. It will spin every now and then, but typically nothing after that initial burst. While the impeller does move by hand and is not locked, it seems like something is causing it to quit.
My next step is to try the pump with the original pump casing and see if it works that way. I know this Bitspower pump top works because I have seen this combo in youtube videos and in the "Dream Machine 2012" Maximum PC build. Koolace as stated prior did have some issues with their pump tops causing trouble, but I find it unlikely this to be the case otherwise others would've known it by now just like with Koolace until they fixed it.