....have you tried a Safe Boot? That would seem to be an obvious step when troubleshooting long boot times.
A Safe Boot gets me to the log-in window in only 3 minutes. However, although the cursor moves, the log-in window does not accept instructions from either the keyboard or the trackball.
I did a forced shutdown and used the opportunity to once again do an SMC reset. I figured it couldn't hurt.
EDIT: I have since used OnyX and it found two versions of each of these:
Canon IJ Network Scanner Selector EX (5.2.0)
Canon IJ Network Tool (3.2.0)
Canon Quick Menu (2.0.0)
Each pair were the same two dates August 18 and September 12, so I deleted the September 12 version of each along with the associated items recommended by OnyX.
However, little change.
If I have PPC drivers, what tells me that something is a driver? How will I know which is PPC or Intel?