1. M class for Y -> W, R class for W -> J
2. There are a number of services which will allow you to look at the fare buckets available for a specific flight. While award/upgrade buckets are not normally shown, if E class seats are of limited availability, upgrades from Y will be even more limited. You can also check Asia Miles/MPC to determine if classic award seats are offered. Note CX policies in these areas seem to have been changed in the recent past.
3, Some one else will have to answer
Happy wandering
Fred