Don't take this as a game, it's simply a tech demo by Square Enix displaying their future technical capabilities. It does, however, look very impressive and has the name Agni's Philosophy.
Looks fantastic, which is no surprise. It is Square Enix after all.
I would be perfectly okay with this being the basis of FFXV. Perfectly. Cutting back on weird hair and ridiculous names is a must in my opinion. As a piece of tech though it looks fantastic. Some of the particle work was excessive but otherwise impressive.
A bit of that is relatively subjective thinking. I felt XIII and XIII-2 were worthy of my time, and the latter had a very limited cast of characters compared to most mainline entries and it's story - again while its quality is largely subjective - didn't throw around deux ex machina and contradictory plotpoints. In fact, it played by the rules set by the plot fairly well (demonstrated by the ending, for example).
I don't want to come off as overly defensive of the series. I do see what you mean overall, wanting something like Agni's Philosophy being the groundwork for a new Final Fantasy. It would be an interesting direction for the series to take. In fact, it's a shame this isn't a real game in its current form.
No, we probably won't. Versus XIII is vaporware, and Square-Enix is slipping.
General negativity towards Versus XIII has been a running joke since 2009, realistically speaking I want to play the game.