I should note that all of my arguments are under the assumption of an ideal party setup; that is, a (reasonable) tank, a (reasonable) healer, and a utility (WAR for red, BLM for grellow, etc.) If you are soloing or duoing with two melees, for instance, I do not consider that to be ideal, and thus /DNC or MNK/NIN becomes viable. When I call /DNC a gimp subjob, it is in the context of an ideal party setup. Sorry for the confusion. That said I have a few more things to touch on.

How many of those 4x was a BRD spell?
Those four times were with Threnody, sorry I was unclear. The point I was making was that just because it so happened to occur once doesn't mean that it is the norm.

I am on no specific side as I know that NIN and MNK are both great tanks. I don't believe one is "better" at tanking then the other because that depends on player skill, gear and atma of course. So I will be honest - don't really have an argument there. From your original post I had that "MNK's pwn" impression - In which I stand corrected. Yes MNK's suck at red, and ninjas have a lot more options in that department.
NIN and MNK are both great tanks, I agree. THF and DNC are also passable tanks. PLDs are bad tanks. Conceptually, MNKs are superior tanks to NIN, player skill, gear and atmas have no consideration when discussing a class theoretically because the classes should be assumed to be played at their best.

That is not to say that MNKs are always the superior tank. Indrik is a prime example of a NIN fight; being able to bypass Scintillant Lance as a NIN is huge when it will regularly one shot MNKs is a huge boon. That said, fights where NINs are preferred over MNKs are few and far between, which is why MNK is superior.

And because someone will comment on the PLD can of worms I opened, PLDs are bad tanks because they rely on cooldowns, MP, and do not bring damage. MP I know is not a big issue in abyssea, but it is a limitation nonetheless. Cooldown dependency is a big issue because once you pop your enmity generating abilities, PLDs are a sitting duck for a DD to TP on the mob and steal hate. Their inability to deal damage is worse than you might first expect because once Johnny DD steals hate, PLDs have a hard time reclaiming it, opposed to a MNK or NIN who can easily WS to reclaim hate. Extended fights are even worse due to the enmity cap. The final nail in the coffin is a vast amount of abyssean NMs utilize hate resets. Aside from their cooldowns, PLDs cannot easily reclaim hate with a WS like NINs and MNKs can.

Enough about PLD.

- You're right about the 90% thing, I just mean there are really good chance to proc red in a nin+blm duo (subbing war adds seraph blade and raiden trust to your arsenal, no more no less), and pls explain why you think i shouldn't have an event polearm (which i have since 2005)
/WAR gives access Red Lotus Blade, Seraph Blade, Earth Crusher, Seraph Strike, and Raiden Thrust. That is five more or a 38% proc rate increase. I figured you didn't have the event polearm because you seemed to favor using /DNC which implies that you care/know little about red procs.

- I doubt a mnk/nin can land hojo, since it's a nin48 spell. no need of further explanation about that.
Who cares about Hojo? The only non-elemental ninjutsu is Kurayami.

- mnk+whm guarantees blue procs during 22-7. If you're farming af3+1/+2 item, going mnk+whm simply doesn't work that nicely.
There is no gear that drops from +1 or +2 NMs that is worth giving up grellow procs for. If there is some piece of gear that you simply must have, then save a pop for blunt o'clock.

- /war and /dnc depend on what you are fighting: for example kiting briareus every miute after a tp move hurts your damage more than throwing a violent frlourish. just choose the appropriate sub for the situation (or choose your favourite one).
That is a highly specialized reason for /DNC. My arguments are for general purpose, typical day-to-day Ninja-ing. /DNC for stunning Briareus is a good use for the sub (but then you have to leave abyssea and lose your lights and time, trade-offs!)

Sorry for the punctuation, but i'm not an english native speaker when i see someone writing in italian i usually try to help him/her improve instead of complaining...
For what it is worth, this post was leagues above your previous. For the future, try to consistently use capital letters and punctuation. Grammar and sentence structure is far less important.