Nice idea. I would suggest making old world dungeons unchained and give rewards that have critigation for armour and crit for weapons, but with rewards only as good as say lvl 1 or lower of Khitai faction gear, and lower than tier one raid gear.
Providing AA XP while levelling is also a nice way to reward maybe 30 AA points to new 80s who have played through the game, not just used offline levels. This is not so good for guys who want to make 80s alts, but does boost pop in below-80 areas.
The single server tech would be awesome. I have thought that it would be a good way to get more pop for all aspects of the game, PvE and PvP.