FFXIV Heavensward: I like the idea of branching classes like summoner and scholar
The way the current system works is that the lvl 1-50 skills are for the arcanist class, and by extension, can be used for the jobs that branch off of that base class, summoner and scholar. With this in mind, it makes it hard to balance skills for classes and jobs alike, since they share them, and if the roles change, it makes it even harder to balance and maintain. I'm going to use your Lancer example with Valkyrie as a new job. You have to make skills especially for tanking and dps into the lancer class so that it will build into both. Much like Arcanist having skills for healing built into it so that Scholar has some things to work with. Without physik, and res built into arcanist, they'd have to put those on the actual acholar crystal, leading to less skills they have as they level up and progress.
Actually I'm not sure he did. He's don't a reat job theory crafting and creating interesting twists on new/old jobs and how they can branch but he appears to be pressing more into distinguishing the split than formulating it into a workable job. The best way I can explain this is falling into the trope of "Cool but Impractical". I've seen a lot of job ideas on here that do that. They don't take the time to flesh out the idea as a whole and build upon it.
I haven't read them all but take for example his Rune Knight idea, as a healer. While healing your allies with attack is interesting, it becomes impractical if you are in the "danger zone" 100% of the time, you need to be able to heal from range. And his Reverse skill, while a good idea might be a little hard to implement, but that is just a thought. Dancer also have no Raise skill a must for all healers. Valkyrie seems good but if you look closer he doesn't explain the "stacks" that you are supposed to accumulate, where do they come from?, no skill seems to grant them. Ideally a Tank/Off-Tank stance would grant those effects. And while Corsair seems like a nice split for Marauder, a Beast Tamer might fit the class skill set better.
However, despite a few issues here and there. I think what he is doing is a great idea. He's trying and thinking of new way to implement jobs from the old class system, which I like, XD. Plus he is making the new abilities/skills appear the way they do in game which helps immerse the viewers in the actual feel for the skills. Something I'd like to do but don't have Illustrator/Photoshop right now.
Please keep at it, just remember to think of the job as a whole and how it will flow at each instance. Try not to add in too much to each skill, nor make it complicated to execute while performing the jobs mechanics. If ever you'd like some assistance or feedback feel free to ask and I would be happy to help.
PS while most of the branches you made have some minor adjustments. I would look into Necromancer, the idea is solid, but having it branch of of Black Mage might be an issue based on the mechanics inherited from Thaumaturge.

Jun
FFXIV is a very different game
You wanted your FFXIV DPS to not take AoE damage. However, it was nerfed so that AoE attacks wiped off Shadows, but it still was more effective as it still blocked moves.