I had a thought of some vendors you could add.
1. Vendors with pre karazhan gear or d3 and shields/plate/rings etc etc because it will be alot easier getting ahold of gear and people will need to raid for the upgrades when it comes to rings etc as it's free t4.
2. Professions vendors for say if someone wanted to level enchanting but to get the mongoose and other recepies they would have to do karazhan and higher instances.