RUN is a novelty job and will never be considered a tank in it's current state. It is quite obviously not an acceptable tank for anything serious just from looking at it on paper. You made the choice to level and gear it for whatever reason, hoping to use it as a tank to... everything? Anything? There are no encounters currently where it excels at anything more than being a support job in the game. This is not the fault of other jobs being "overpowered," but the using the job simply being kind of silly. It's my perspective that the job needs a complete overhaul in order to be an effective tank or even support tank.
If you want to tank all content, then level various jobs that can tank (PLD, WAR, NIN, MNK) and gear them instead of whining. Aegis take a couple of months work, Ochain can be done by a PUP in short time if you're focused, I'm sure.
But, hey, we can all cry for nerfs, I guess! Surely, that's the best way to balance the game instead of simply making yourself available to fill what the task at hands needs!
I think RUN is overpowered because it has UNPARALLELED access to Runes that other jobs do not. Please make PLD, WAR, NIN and MNK just as good at using Runes and Big, Shiny swords as RUN, Square!