I second these 5.1-Old talent trees, in my opinion they where simply better with more options than we have today.
2-Darker theme, where you actually fight for conquest; to kill and enslave.
Profit from war, not fight to protect/save.
3-Long leveling grind with a big ammount of zones 40+ would fit draenor, (8 zones is an island not a world/contient).
4-Increased leveling difficuluty, boost the damage of mobs in the 1- 85 range by 800% & their health by 400%.
Bring back group & elite quests for leveling.
5-Return of the vanila style lengendarys, a sub 0.02% ultra rare drop *mythic only* not just a quest everyone will be expected to have/grind for.