These are all my own opinions, so take what I say with a grain of salt, as I read over everything that was posted and giving you constructive feedback. I will say I like your post, and I like your ideas very much.
I think what your suggesting has -too much- utility- The concept behind this RDM is a magic swordsman, but the key element of the job in this suggestion is utility.
Dragoon is pretty simple in terms of how its played, don't let the illusion that other jobs are more complex change how you feel Red Mage could be.- This being said, I know this has a low chance of implementation because the gameplay is a lot more simple than NIN or DRG or MNK. I do like simple gameplay, though I get the developers don't agree with me on that.
I think thats to much power for the utility it could possibly have. I'd say more akin to a bard, since they'd be more of a support role, rather than a pure dps.- To those curious, this job should be doing NIN-level DPS.
While I can see why you would want CNJ and THM to be its crossclass skills, I'd say unless they get some kind of weird potency change because they are RDM, CNJ just isn't good for them. Protect and Stoneskin would be great, but Raise would be worthless without a trait to battle raise. ACN over CNJ might be a better choice, as you'd be able to make use of Virus, eye for an eye, ruin (which could potetially, be useful with your double and triple), as well as Ressurection, and physick. This would only add to the classes utility overall. This contradicts what I said about to much utility, but if the dps were lowered overall, this would be awesome to have.Cross-classes: CNJ (Stoneskin, Cure, Raise, Protect), THM (Swiftcast, Surecast, Blizzard II, Sleep)