As a tank I hate having to have all marks taking up space in my hotbar. It's also pretty annoying to have to either waste a keybind on marks or waste time individually clicking the monsters then the mark on my hotbar.

Double-clicking to mark a mob should be implemented. Both on the mob itself and on the enmity list. There is already a system in place to see which mob is 'next' (Letters next to their names). In addition, double clicking the next mob (In alphabetical order) on your enmity list should automatically mark that mob as '2', and '3', and so on.

I feel like this would make tank's lives a little easier.