His d'c is mostly a part of the game not allowing him to clip.
Also, He's using a known bot, and there is only 1 that clips.

As for the cheating happening in PvP, I see people use Sprint+1 often almost 1/1 in every game. Always 1, usually a mage or a warrior.

And SE will never do anything about this, in FFXI it's a given that everyone cheats and it is acceptable, even preferred.