1) Can't help with this one, maybe someone else will chime in...
2) Yes, set all speakers to Small since you have a sub. Audyssey looks for the -3dB point for each speaker in "your room" and reports back to the Denon, based on that since the 80's are capable of 40hz, Denon uses the setting of LARGE. For my setup I put my 80's and 180 to small, and experimented with 40hz crossover by raising to 60-80Hz. The sub will do a better job in the lower freq regions.
3) Assuming you are running the primary (central location) as the first measurement which for distance/delay, followed by the rest of the locations (8 in my situation) to form a "bubble" around the listening area, you should not have to adjust much. You never want to "lower" a crossover point found by the Denon, but increasing is ok. Also, adjusting the speakers to Small is fine as well.
