It would appear that the last sinister bubble to show up after cleaning the CPU block simply needed to be bled. At current, this is my CPU block after 15hrs+ of operation:
I'm going to consider this issue closed unless the bubble shows up again. I would to thank everyone who endured this adventure with me. I have learned a lot. Ultimate lesson here: PLASTICIZER FREE TUBING FTW!
Thanks again guys, I REALLY appreciate the help!!!