I hear you David,
The fibre dust from the panels was a big concern when I chose them...I went through all of the different types and found one which I found the least offensive. For me, it was a question of risk management. Which is/was more problematic: dust from the insulation/joists/pipes etc or potential dust from the panels? I went with the latter.
Joey, another tip...If you find light leaks around the perimeter, you can use a can of that expanding foam insulation crap. My inlet pipes to my sink, like yours, come from above. I used the expanding foam in the corners and around the pipes to eliminate light leaks. It works perfectly.