Gunblade...that is all

[Kitru]

First of all, you're wrong about swords being heavier than most people think. It's the opposite. Historical swords were in fact much lighter than popular depictions, especially greatswords.

I've dealt with people using swords for the first time numerous times. They are heavier than most people think because most people don't realize that swords are big chunks of steel. It's why the first instinct of most people when wielding a traditional English longsword is to use it in two hands instead of the one-hand that it's intended to be used in. What most people confuse the overall weight with is the *balance* of most swords which, assuming it's actually a well crafted sword that's properly weighted, makes it remarkably easy to swing once you've gotten used to the weight. The substantial weight of a combat ready sword is the reason why fullers were developed, in order to cut down weight without reducing structural integrity.

This is, of course, when dealing with weapons actually designed to hit hard enough to cause significant damage. Sport weapons, like fencing epee/foil/sabers, are much lighter than most people think because they're not supposed to deal damage. The show weapons that people put on their walls are also lighter because they're not made for combat: they have partial tangs and are made with inferior steel because neither of those aspects makes a sword look any less impressive and it has the benefit of making it cheaper (and therefore easier to sell).

Secondly, there are no real world principles in this story. Just sticking to the weapons, have you SEEN the shapes of some of these things? They would break in half on the first hit if they didn't stab the user in the eye first. Applying real world logic to a world where a book is a viable weapon of war is a fruitless endeavor.

The real world principles apply as far as the willing suspension of disbelief is concerned. The Rule of Cool that I mentioned before and the willing suspension of disbelief are at odds with one another. People are easily willing to suspend their disbelief such that a book is a weapon of war because they already suspend disbelief concerning magic: the book is an instrument of magic and magic is itself the weapon of war, not the book. People are willing to suspend disbelief concerning unrealistic weapons and absurd armor because those are aesthetic choices; axes and swords are practical weapons of war, which is what matters more than what the weapon itself looks like.

People are less willing to suspend disbelief concerning completely unrealistic weapons like gunblades, buster swords, and personal minicannons, which is why they are accepted only when their use is exaggerated by the Rule of Cool: there is less willingness to suspend disbelief and it only gets overcome by the exaggerated awesomeness of their use.

A lot of it depends upon what environment the developers are attempting to foster. The more you delve into the Rule of Cool the more audacious the environment becomes and the less "real" it seems (and, yes, realism matters even in fantasy games, which is why axes are slow and daggers don't hit hard), which is what the developers must decide for themselves.

Third, Amano does not have a belt fetish, you're thinking of Nomura. Amano has a bead and pattern fetish.

Yeah, forgot that Nomura took over on 10 with Tidus having an entire arm covered in belts while Amano worked on it, but Amano was in charge of 9, where you've got Wedge who is, quite literally, dressed entirely in belts along with massive belts or a series of belts being a highly visible aspect of most of the main characters (especially Steiner). The dizzying array of sashes that Amano tends to use (especially on 6) that I was conflating with the belt fetish probably fits in better with your "bead and pattern" fetish, though.

Fourth, it would be very easy to fit into the lore as we already have groups of Garleans opposing the Empire's plans with Cid and his Ironworks.

Cid, Biggs, and Wedge are pretty much the entirety of the Garlean defectors. The fact that gunblades are weapons of the *military* elite further bolstered by the remarkable predilection the Garlean military has towards loyalty to the military dictatorship that the Garlean Empire seems to be, I would find it hard to believe that you'd see defection on a large enough scale to justify adding a player class.

It's not far fetched to have a faction of the military break away and side with the Eorzeans in a later expansion, allowing us to use the weapons and armor they took with them.

The problem with it being an expansion is that the game has the timeline follow the player's level. If the expansion added a new class, new players would want to be able to use it from the start, which wouldn't work with the timeline we've currently got. They would need to either add it as a "prestige" class, similar to how DKs were first implemented in WoW, or change the entire story we've currently got to account for where they're progressing it to, which, given that ARR is a pretty story intensive game (you don't just go from quest hub to quest hub; there's a well defined story that you follow from 1-50+ and the devs have actually said that they think that the story is very important).

Who's to say the Garlean Empire does not have its own classes and guilds as well?

We already know it has its own classes, given the various Garlean units out there and their consistent names: Garleans have Medicavi instead of Conjurers, Hoplomacavi instead of Gladiators, Eques instead of Lancers, Sagittarius instead of Archers, Signifers instead of Thaumaturges, etc. One could probably make the assumption that there is something akin to guilds within the Empire, but they're pretty much guaranteed to be as ensconced within the Garlean civilization as the Eorzean guilds are to their own nation given what the guilds represent (a formal organization for the training/accreditation of practitioners as well as a collective for negotiation and interaction with other large scale organizations such as the governing bodies of states and city-states).

I'm not saying that there's no chance whatsoever that we'll get a Gunblade wielding class; I just don't think it that it's likely given everything involved. We're a lot more likely to get a bunch of other classes before we get a Gunblade class.