The combination of sword and magic is something that has
potential, maybe, but either way it lacks the precedence that your signature implies with statements like "It's
supposed to be this instead."
Supposed to according to... your headcanon?
Ignoring your appeal to authority (because the FFXIV devs are absolutely infallible), it boils down to looking at the elements that make up the job and what makes sense given that knowledge. If you tell me a class is built on a combination of sword and spells through concept and aesthetic (RDM), then I'm going to expect to see that well-represented in gameplay. I can understand if there's limits or things that can't be done in one specific medium/genre, but that can only be taken so far.
And you can't call it my headcanon when the idea sprouted from SE's own games. While FFXI helped the concept evolve, RDM was always the FF series' original hybrid. You can't even say this is something only I wanted, as there were also threads asking for a RDM with melee & spell mechanics (partly to avoid Refresh-botting, partly because the sword should not collect dust) going as far back as the beta to ARR.
And personally I'm not against RDM gaining similar skills here -- in fact I've suggested as much many times. However, to nebulously state that 11's ideas "should be built upon" without any mention of how to do so in a way that would have separated it from its contemporary Rune Fencer comes out as a lofty demand with no thought towards practical application.
Well, since you were nice enough to ask, assuming we want to go with sword enchanting as a mechanic for RDM, you can go the route of building a resource that can be spent piecemeal on sword enchants. An alternative would be combo bonuses where following a spell with a specific sword strike grants an enspell buff that lasts for something like 20-30s.
Assuming you want melee & magic mechanics, you can go the way of weaponskills granting RNG procs for instant spells, melee skills granting a stacking buff that reduces cast time of the next spell, or melee strikes building a resource that allows certain spells to be cast instantly. To ensure the rotation between sword and spells is followed, have melee strikes gain a secondary effect if used after a spell, or have spells apply a short debuff that increases damage taken from your melee skills.
Mind you that neither of the above are mutually exclusive, but given the FFXVI developers' understandable aversion to button bloat, there's that to keep in mind as well.
As for Rune Fencer, considering the concept of the job (cast Flare Sword => whack away at target), sky's the limit with what you can do with it. A long time ago I suggested having it brand enemies using sword skills and then doing something with said brands to deal damage. An alternative would be charging their blade with elemental runes and once the runes have grown strong enough (what I called "maturing") spend the runes on elemental sword skills. Yet another alternative would be making them a tank that uses elemental runes on themselves to generate aggro and deal damage, or elemental shields.
Hell, you've said nothing about why such expansion would be incompatible with the base we already have in 14!
In order for melee to have a bigger role in the current design, you'd need to:
- Adjust how mana is consumed (you can't automatically consume mana like the current design without adding a second melee combo)
- Adjust how mana is generated (either remove mana gains from everything but Verfire/Verstone/Verthunder/Veraero or make melee strikes generate mana)
- Change melee skill and spell potencies (buff melee skills, nerf spells)
- Create an incentive to use melee skills outside of 80/80 (or de-emphasize the use of Jolt so that it doesn't eclipse the melee skills)
- Throw in a mechanic that ties sword skills and spells (sword combo lets you cast a spell instantly)
All of this is very doable (in fact, most of these come from
a thread I made shortly before Stormblood launched). It's also very unlikely because the devs said they wouldn't do an overhaul again after WAR during ARR.
Besides, I'm fairly certain that Embolden was the devs' attempt to provide an En-spell in the absence of an elemental wheel, particularly when it was released in an era where all melee jobs provided vulnerability debuffs to physical damage types but only SMN had a magic damage buff.
Embolden was more an excuse to say "hey look, you have party utility!" than anything else. Their attempt at enspells came via the enhanced melee combo. The live letter after the reveal had Yoshida say as much (since he referred to the combo as the 魔法剣 or "spellblade" combo).
Because without Dualcast RDM would not have been in FFV. It wasn't a natural element of the job, and instead something pulled out of the ether. If delay reduction between spells cast had been a thing for RDM since the first Final Fantasy game (like maybe spells cast by a RDM always go first in an attack turn), I could have been convinced that it's just natural progression for the job. That, however, was never the case.
Dismissively saying it's "oversused" [sic] doesn't
actually invalidate the point being made.
If you want to discuss points connected to RDM's design and concepts, I'm all ears. Using the mage argument basically means you have no real points, as that argument is used in bad faith to try to kill the discussion.
"Mage who uses both White and Black spells (but lower ranked, with other stats to compensate, including in melee areas)" versus "Knight who employs Combat Magic"
What I'm arguing for doesn't move RDM into the latter. If anything, it's essentially the former but actually putting the entire concept to work. Bonus being that it'd be true to how the job is presented in-world for once. FFXI had RDM as more than just mere mages, making the player want to be like Rainemard (especially once you meet him during Wings of the Goddess) instead of the Refresh-bot that hangs in the back lines. Likewise, FFXIV has the whole crimson duelist thing but then gives us gameplay where the sword is an afterthought. I get that SE has a track record for pulling crap like this, but that stopped being funny at around the time of Vision of Abyssea.