DING DING DING DING!!!!

I took reptilezed advice and gave it a good yank, and sure enough, the compression plug loosened. Initially I was hesitant because I wasn't sure if it had seized, but it is now loosened. I managed to push the compression plug lower thereby closing the gap between the top of stem and the top cap. I added a 5mm spacer (for a total of 15mm) underneath the stem and left no spacers above; this accounts for the +3mm of stem height above the steerer. The extra 5mm rise of the stem, thereby the handlebar, will be addressed when I go back to the LBS.

To Burton, thank you for your reply. It is a carbon steer tube, so yes it was a compression plug. I don't plan on cutting the tube just yet until I get the fit down pad, and have spacers available at my disposal.

Question:
I know the stem bolts are tightened after the top cap is screwed down. When tightening the top cap, does it have to be tight or loosely tighten onto the stem in my case.

You guys are great, I was afraid I was going to get reamed for this newb question.
-Jeff