Considering that it generates a lot of arrgo, Defense was worthless in general due to level difference, and anything outside of a Paladin with Aegis prior to recent update basically tanked just about as efficently - yes anything that went /nin and could maintain hate was the tank in 11. DRK did it well due to stun, soul eatter, and it's damage output. Cata regenerated your health which also gave higher surviablity.
Sam was designed as a tank as well. It was actually common to have Sam/nin tanking in Sky.
Mnk made a decent tank as well too, the only thing that really killed it is that it fed tp like crazy and caused things to go kinda side way on higher level content.
Thf was decent at evasion tanking more so when it started getting it's hate stealing abilities.
Bst literately soloed things due to the durability of it's pets.
Never seen a WHM tank before due to them running out of MP due to cure bombing, as that is there only way to keep hate on higher level content. Benediction is a good hate spike but that would be a waste and overtkane
Yes, because for long fights anything in 11 needed time to build hate. The most efficent way to do it orginally was through RDM and it's enfeebles. Drk knight could do it just as well though as long as your group was ok with doing damage. Stun has the same enmity generation as Paladin's flasth. Soul eatter and Last resort are basically 2 instant provokes. Then it's high damage stacked on top of it would allow for a drk to keep hate in the same fashion a Paladin would, they were just better at it due to th high damage, because unlike 14, the damage you dealth = your enemity. There were a few abilities that upped it for spike hate, some placed on jobs that would be considered "Dps" on 11, such as Warrior.