OK, I'm trying to follow the air intake passage ways just to make sure they're clear. Air Cleaner assembly is fine. There's a flexible tube that connects the ACL to a hard plastic channel. This channel is mounted to a hole in the frame. How does air flow from inside the frame to this channel? Where does air flow from the outside into this part of the frame? I just want to check to make sure there's not blockage from dirt or dead insects or stuff like that.

Well it sucks air that is between the inner and outter fender panels. I assume most of this air is drawn in from behind the head lamp as is the case with most factory intakes. Keeps hot engine air away, and provides a quiet suck-place.