Concept for a Magic Melee DPS

[Archwizard]

Since people don't want to see off-topic arguments

I would say it's very on-topic, as I am arguing that your design could be adapted in part for exactly the kind of Magic Melee DPS this thread is discussing, if you would simply stop insisting it's RDM or nothing.

I'd have no problem with Mystic Knight having a party-wide damage mitigation buff, though the overlap with Tactician makes that somewhat risky. AoE weapon enchants as the job's answer to Battle Litany/Brotherhood is something worthy of consideration, though that would really make me wish stuff like Foe's Requiem would make a return.

There are enough overlapping skills already in this game that I won't even bat an eye at it -- hell, there's enough that Tactician literally names two of them as skills that should be used sequentially rather than stacked, and that's still not accounting for the alternatives brought by healers and tanks that can be stacked, like Asylum, Temperance, Dark Missionary, etc.

Alternately, something that might be even more fitting, a mass EnDrain. Give everyone a health leech as an alternative to mitigation or HoTs.

If the sword is to see any significant use (read: more than once every 45 seconds), the job would have to stand in the front lines.

Let's not get wires crossed here. "More than once every 45 seconds" could be "Once every 45 seconds unless you hit Manafication to bring that down to 20 sec every 2 minutes" or flat out "Once every 40 seconds" and still fit that criteria, which is closer to what we have with Scorch anyway -- but we both know that's not what you're asking for, is it.
Which brings us back to "you've designed what is, at its core, a melee job."

Between? The instant-cast buff is attained after the second weaponskill in the combo. You essentially have the choice of ending the combo in an instant spell (that generates gauge, deals higher damage, and can be used on a target outside of melee range) or Death Blossom (which increases target's damage taken from your spells for 30s).

... Yes, it's at the end of the combo, which means it's right before the next combo. Unless the spell you're casting is Death, there is a follow-up, so its still jammed between two melee skills.

Slight aside: Have you considered "Imperil" as an alternative to Death Blossom? It's a skill from FF13 that increased the target's vulnerability to magic.

So you'd do nothing while out of melee range?

You have levels in 6 out of 8 tanking and melee jobs. You have experience, so use it.

Realistically, at any point you're out of range of the boss as a melee, one of three things is happening:
1) The boss is moving, probably because they have some kind of dash attack. Your best bet is to close the gap as quickly as possible so you can return to comboing, not to stand still hardcasting a spell.
2) Bullet Hell phase. Your best bet is to keep moving and throw what ranged attacks you have that won't stop your run, because if you stop moving for any considerable period, it's very likely you'll die. It's exactly the scenario that would have doomed an unprepared BLM's DPS before ShB, exactly what RDMs gained Reprise for in spite of Dualcast (and bear in mind, without the guaranteed Dualcast, you can't reliably slidecast either), and exactly why every single melee's ranged attacks are instant effects.
3) The boss has some kind of physical impediment preventing you from reaching them with melee for an extended period, like the Ice phase in Thunder God. Assuming the boss isn't completely immune to damage at this point anyway, there is probably something else for you, as a melee, to be doing other than standing around spamming spells on the boss, like wailing on an Icewolf instead.

By design, the number of scenarios where a sheer amount of specifically ranged power is required, particularly of a primarily melee job, is minimal.

That said, this is actually something I've been mulling over, as I once had a stand-in for Jolt with a 100% change to proc Dualcast but was told it made the design unfocused. I could bring it back by changing the write-up's version of Jolt to 100% proc Dualcast, reduce the gauge cost to 15/20 and nerf its damage to 100 potency. So thanks for the feedback.

So, use an instant to pop Dualcast.

Good luck making us any less of a rezbot in that case.

And as I've said, NIN's magic is gated behind the ninjutsu recast timer and Ninki.

If you think the availability window of NIN's attacks is relevant to the point I'm making, you're missing the forest for the trees. It doesn't matter if NIN only gets a spell out every 20 seconds compared to your design getting out one every 7.5 seconds -- at the end of the day you're still launching fireballs at point-blank.

The difference between having a cure (even a weak one) and having no cures at all is still notable

Tell that to SMNs when they complain about Physick, tell me how that goes.

You'd need to increase the threshold for difference between white and black mana if you want to go that route, because otherwise you'll hit imbalance the moment you do melee combo => Verflare/Verholy => Scorch => Verstone/Verfire. As it stands, the system is set to bring you within a hair of hitting imbalance, so messing with the amount of mana generated would call for a change in that.

If you went the route of scaling up the Mana gained from the existing Verspells, sure. There are plenty of other ways to increase Mana generation without just buffing the spells that can contribute to imbalance.
For instance, introducing new spells that generate Mana more efficiently, as seen with Scorch (and I expect is the most likely way we'll see our combos speed up in the future). Introducing traits like Improved Manafication for other Mana-relevant CDs and effects, like Acceleration. Adding Mana to oGCD skills like Fleche, or increasing the amounts generated by our Mana-balanced spells like Jolt. Introducing abilities to hasten our spellcasting in general.
And if you loathe the idea of buffing casting somehow, you could just straight-up reduce the cost of melee. Tons of ways.

Who's saying that? I haven't seen anyone say that. I've seen people say they play RDM because it's the closest thing to a mystic knight that we have,

It would also be far stronger overall and steal players away from RDM who want a spellsword type class.

Sounds like there's demand for Spellblade then. Why not just let them have it, rather than holding that fantasy ransom to RDM?