My Ninja is only level 43 but I don't think it's really hard to memorize them. If anything, the easy way to memorize Ninjutsus is based on whether it's a 2 or 3-string combo, and which one you end with, without any repetition. Since I unlocked the 2 strings, I have never used Fuma Shuriken so I won't take that into consideration. The only thing that makes it "hard" if any, is the Mudra lag (which they addressed as something that cannot be looked at at the moment).
Ninjas do not have any additional enmity generation on their skill, so to nerf their enmity generation is to nerf their DPS.
I do not play Monk, nor do I really do or know anything about Final Coil, but I don't believe Dragon Kick debuff stacks. It really doesn't make sense to stack Monks because Ninja can still provide Vulnerability Up via Trick Attack, and still has utility over double stacking Monks (ie. Goad, Ninjutsus). Their DPS won't be nerfed out of the water, but will probably be just toned down a little. It won't really bring about the end of the job.
