After thinking about this, I switched out the M3X20mm (#241) screws for M3X16mm (#242) screws. This seems to be a better fit, with no play between the extruder block and motor. Hope that help someone else out if they are following the directions to a "T".
#2 - So I pushed the Large Extruder Gear and hobbed insert assembly into its position, and it functions quite nicely, however the bearing is so firmly lodged into the extruder block, that I'm certain I will break the large gear trying to pull it up and off if I ever need to clean/reattach the hobbed insert. Going at it from below and pushing up on the M3X20mm Hex head is the only other option I can think of, but there's not much material to get a firm grip on the block. Is there any nifty tricks to getting this assembly out that I'm not seeing as of now?