I'll preface this by saying that I'd like to see less dual/omni role job suggestions and more focused ones instead. The point of being able to level all jobs is to cover this omni-character desire without compromising the design of the jobs themselves. Focus on one idea, first. If FFXIV was more like WoW in that you pick one job identity and stick with it, that would make more sense. XIV is not WoW. Yoshi-P even thinks that Arcanist branching out into Scholar and Summoner was a mistake.

That said, I also don't think Monk should lose their Greased Lightning and Forms. That is the core of the job, not the elemental fists and Chakra. I agree that the latter two systems need to be integrated into the former more. And I can think of some rough ideas on how to integrate the former mechanics into each current role while staying true to XIV's design that you glossed over. Not the generic "support" and "prevention" roles you suggest.

Reading these abilities over however, this feels like something you'd see in an older MMO based on D&D style design. That doesn't gel at all with how FFXIV is. I feel like you are missing the mark of what fits this game and what doesn't.

I'd say try working within the constraints of the current MNK and show how it would work as a healer or tank rather than throwing it out and adding abilities that SE would never add into the game as it is now, rather than trying to force things that the design team has said they've scrapped.