The Amaro mount...

[Shougun]

also other weird thing is that level 80 dark knight class quest should have given you the level 80 skill but no, you just learn it automatically when you reach level 80 (maybe other classes have similiar quests which clearly should teach you the last skill too).

I think this was done to avoid another level 70 capstone MSQ trial and a bunch of people without their level 70 skill queuing making the trial much harder than it would have been normally.