2nd Job Predictions

[Kuwagami]

snip

a scythe for a DRK would be a terrible idea. I don't know why they came to the idea that Grim Reaper-like knight were somewhat cool, but DRK are traditionally 2H-blade wielders. It also fits much more their most common spell : blood blade.

For the samurai, why wouldn't they make a katana related class ? it would fit samurai, ninja and even blue mage (saber/katana wielder in FFTA). Though ninja will surely come with dual dagger class, and samurai would perfectly fit the lance.

Regarding weapons, I'm 95% sure the game must have each weapon be main class + optional job. (To allow unequipping job crystals)

So if for example Conjurer would go RDM with swords, it would mean Conjurer could equip swords too. Which is unlikely.

So my own speculations would be things like Gladiator - RDM, Pugilist - PUP, Marauder - DRK, and so on.

The remaining issue from this, is how some jobs would not offer much variety to the existing one. (Unless say DRK would be a debuffer more than a DD)

Not necessarily if we consider that RDM is probably going to be a 2nd tier job. If they work as they were advertized by Yoshida, It would be possible to come from WHM or BLM (for the example of RDM). RDM using basically rapiers (which wouldn't really fit GLA either), there would just be a need of somehow relating the job as a spec.

To put it simple, RDM was used as an example where having WHM and BLM both at lv50 would allow to unlock RDM as a 2nd tier job. But having it 2nd tier means that you can come from either BLM or WHM to become RDM, which is troublesome if we consider the weapon restrictions.
However, having a single rapier, utterly useless for the classes (on par with iL50 white quality), and obtainable uniquely via the job NPC, which has WHM/BLM/RDM as job restriction, would somewhat work. When thinking of it, the animations of both jobs' spells could fit a rapier's use (at least the character would not pierce his own flank while swinging it). And if it's only one weapon, it would allow the change of crystal the time to create a set (no reason to remove the crystal afterwards anyway). Then every other rapier would be RDM-locked and it would be good.

[Caselia]

Regarding weapons, I'm 95% sure the game must have each weapon be main class + optional job. (To allow unequipping job crystals)

So if for example Conjurer would go RDM with swords, it would mean Conjurer could equip swords too. Which is unlikely.

So my own speculations would be things like Gladiator - RDM, Pugilist - PUP, Marauder - DRK, and so on.

The remaining issue from this, is how some jobs would not offer much variety to the existing one. (Unless say DRK would be a debuffer more than a DD)

Those who did not play 1.0 would most likely not know this. But Yoshida said before that classes will be able to use different types of weapons like Gladiator eventually being able to use Greatswords (this was an example proposed by him), because they can already access daggers/swords which gives them a variety in which weapons they wield. So take this into account for specifying your jobs sirs and madams.

[Malamasala]

Those who did not play 1.0 would most likely not know this. But Yoshida said before that classes will be able to use different types of weapons like Gladiator eventually being able to use Greatswords (this was an example proposed by him), because they can already access daggers/swords which gives them a variety in which weapons they wield. So take this into account for specifying your jobs sirs and madams.

Two different view points. I don't disagree with your view that a class can go from swords to great swords.

But remember that if a job like RDM is supposed to have swords, then the class will also have swords. And while not impossible to go from staffs to swords or bows to swords, it seems less likely than go from swords to swords.

[Caselia]

RDM isn't iconic to using swords, it's just one of the type of weapons it was capable of wielding. However if Yoshida wished to make RDM wield swords highest chances are it would branch from a new class that fit it's description more than Gladiator. Fencer is an example someone proposed earlier that it could branch from, but then we also must take into account Advanced Jobs, sadly I don't know how they will work, although I can see RDM being an advanced job because they're suppose to be able to use Black and White magic. Although they can still use Black and White magic as a regular job, it might seem gimped depending on the base class.
Edit: The base classes we have now just do not fit Red Mage other than Thaumaturge trait wise.

In Final Fantasy 1 the Red Mage becomes the Red Wizard and could use all weapons. Even as a Red Mage he could use swords and daggers. Do you have examples of red mages not using swords at all?

As someone said after this post. I never said they can't use, I just said it's not iconic to the job. But if you want examples of RDM not using Swords at all ask people who played FF games and when they never used sword on RDM is all I can give as they are the jack of all trades they can use any weapon they please mostly. Swords are just not the main icon of their job. I would quote another post to correct their information, as they base on google, swords are iconic to RDM because they mostly see it with swords does not make it iconic to the job. Also, in Bravely Default which is pretty much a spin-off of Final Fantasy, I used RDM with staffs.

[Lunavi]

One question though: Why assuming that they will run on different base stats and have different roles? We have only one class that splits into two jobs using that data as premise for how everything will be ruled sounds dumb.

[Bloodclaw]

So if for example Conjurer would go RDM with swords, it would mean Conjurer could equip swords too. Which is unlikely.

You just can't say that and have it be true. There are a number of equipment that are job specific and list no class accessibility in the game; this would allow for an entirely new weapon for a job and that job only. Look at the AF armor.

[Kuwagami]

On RDM, they are using mainly rapiers, but can equip some of the great holy swords or a few elemental swords as well, and they are perfectly at ease with staves and rods. (compatibility with cnj AND thm gear).

Also, although their background isn't that much close to conjurer's spirit, they could perfectly come from experiments the thaumaturges would have wanted to conduct on the planet's energy. Thaumaturgy is centered around the destruction and using one's self aether flow to turn their enemies to ashes. If some thaumaturges had decided to investigate and found a way to extract the nature's aether to get more power for themselves, they would have necessarily acquired some knowledge about the conjurer's way, mixing it with their own art to bring an even more powerful use of the aether.

One question though: Why assuming that they will run on different base stats and have different roles? We have only one class that splits into two jobs using that data as premise for how everything will be ruled sounds dumb.

Because the aim of creating new jobs out of existing classes should be to diversify their gameplay. As an example, there is little to no room to create a new healer out of the conjurer, though creating (example) green mage would allow to get a whole new range of buffs as a support job

[Bloodclaw]

RDM isn't iconic to using swords, it's just one of the type of weapons it was capable of wielding. However if Yoshida wished to make RDM wield swords highest chances are it would branch from a new class that fit it's description more than Gladiator. Fencer is an example someone proposed earlier that it could branch from, but then we also must take into account Advanced Jobs, sadly I don't know how they will work, although I can see RDM being an advanced job because they're suppose to be able to use Black and White magic. Although they can still use Black and White magic as a regular job, it might seem gimped depending on the base class.
Edit: The base classes we have now just do not fit Red Mage other than Thaumaturge trait wise.

In Final Fantasy 1 the Red Mage becomes the Red Wizard and could use all weapons. Even as a Red Mage he could use swords and daggers. Do you have examples of red mages not using swords at all?

[Bloodclaw]

One question though: Why assuming that they will run on different base stats and have different roles? We have only one class that splits into two jobs using that data as premise for how everything will be ruled sounds dumb.

I could see the possability that they make an additional job that has the same role but a different stat entirely, but almost sure not for the 2nd job. For example a gladiator becoming a Red Mage but still be a tank. It would be a tank that runs on their own equipment dependent on having equal intelligence and mind balance vs. vitality, would also have vastly different cross-class skills as well.

As game designers they would need to make sure that the new job would not be an instant-win/complete and that the player would need to chose between the jobs to favor; like what we see between the scholar and summoner jobs.

[Lunavi]

Because the aim of creating new jobs out of existing classes should be to diversify their gameplay. As an example, there is little to no room to create a new healer out of the conjurer, though creating (example) green mage would allow to get a whole new range of buffs as a support job

While I see that part I see no hard time creating a new DPS job out of Bard that works in a different way. What I have a fun time seeing though is SE making a healer out of BLM Blizzhealer will be best healer Make it happen SE!