Heehee I guess this video gives away more than I thought!
That looked great! And rather challenging too, I noticed some interesting things here...
My team's a little underlevelled... I actually had to record a couple takes to get one where I won!

A new command called "Bonk!" (Great in-character reference by the way) for Porom,
Thanks, I thought so too! As you may notice, it's greyed out; that's because she needs a hammer equipped in order to use it (she's a white mage, so she can use hammers). It's a nice command but not very polished visually. I may be asking for help on that one down the road.
Tornado being a damage spell instead of 0-9 HP.
It's basically the couterpart to Quake; it hits all enemies, pierces reflect (which is why I was using it in that battle) but is Air instead of Earth.
A set of Black Magic for Cecil and oddly a set of Black Magic for Edge, seemingly losing his unique Ninjutsu.
Ninjutsu was hijacked in favor of a selectable song set for Edward. I figured elemental black magic was close enough.
Rosa has Charge instead of Aim. Dark Knight Cecil starts with the Chaos Blade (Oh wonderful FFT/XII Reference!) in this battle and can equip swords. Coral Sword from Easytype making an appearance.
Since, as chillyfeez noted, you have DK for a lot longer in this one, he needed regular swords (and armor for that matter; he can equip f.ex. mythril/flame/ice/etc gear) to keep him interesting. You can only Dark Wave with a Dark Sword though. Also the Dark Swords and armor usually give him a Wis boost, helping with his magic. I also gave him a bit better HP progression... with his original stats he was having a hard time keeping up with Rosa for HP which seemed like it shouldn't be the case.
The new spells are Awake (I imagine it does what it says), Demi (A very interesting idea for a spell, may I add. The routine was there all along after all.) Berserk as a Black Magic, Warp as a White Magic.
Awake removes "temporary" statuses (sleep, charm, stun, etc), like a mini version of Esuna.
Demi deals 1/4 target's max HP. It seems the only mechanic for current HP is relative to the caster, so I figured this made more sense; so it's more like the FFT demi than the usual demi.
The way I reorganized the effect spells, White gets the "time" spells and Black gets what in FFT would be considered the "Yinyang" spells. So White gets Stop, Slow, Haste, Demi, Comet, stuff like that, whereas black gets Charm, Berserk, Blind, Mute, Drain, Osmose, etc. Rosa, if you notice, only gets the time white spells (in this she's an Archer / Time Mage) and DK Cecil only gets the yinyang black spells (so he'll never get f.ex. Fire 2, but he'll get Drain and even Bio if you level him up enough).
All in all I am impressed by what I'm seeing! I had thought from the sounds of it it would be a tech demo sort of deal, but it seems you are going all out. I can't wait for news for this!
Basically, the plot is unchanged for the first while in the beginning. Enough to fool someone into thinking it's more or less unchanged if they didn't already know any better. But then the outcome of a certain event gets flipped on its head, and this affects everything from that point on. Some dungeons and motifs are the same or similar but a lot of it is just totally new content from that point on. Don't worry, I've got lots of surprises up my sleeve.