I'm trying to determine whether or not a spike counts as an incomplete pass. From what I can tell, it's not really counted as an incomplete pass, at least in the NFL. Although in the NCAA, it's counted as under "team passing", but not attributed to the QB. I'd also be interested in how it's scored in other leagues, like the CFL.
A spike is indeed typically assigned to the "team". For example, you can review the play by play of the 9/23/17 game between Kentucky and Florida, and you'll see at 0:21 left in the 4th quarter this play:
1st and 10 at FLA 35
(0:21 - 4th) TEAM pass incomplete
In NFL statistics, they simply reflect the play as "... spiked the ball", and do not record it as an incomplete pass; see the pass by Dak Prescott 9/11/16 versus the Giants at :18 left in the fourth quarter. The pass is not included in the complete/incomplete ratio. It's unfortunately neither covered in the rulebook nor the guidelines for statisticians.