OKay (cracks knuckles) lets get started.
I would make a new FF with:
less characters that stand for one mood or idea and only change to one other mood to make it seem that they are human, this isnt likable (Lightning, Snow, Squall, Vincent, etc...) and in the end it just looks and if VOed, then also sounds terrible, again, Lighting is the biggest example of this. The only reason I dont state Cloud is because in the actually original game, he was a pretty interesting character who went insane, that, and the writers mom died before he wrote the plot so you can feel the emotion from both cloud and Sephiroth, its not a perfect plot, but it worked.
The setting is utopian Steampunk, a version of it long past the victorian age and has become super advanced, Zepplin airships everywhere, Tall towering cities, and everything looks spectacular.
Theres a alot I could list here, but it would be too long and boring, Combat would be classic FF with a timing abillity for combos and blocking like that of Mother 3. but I want to state one thing.
A character being 17 doesnt make them boring or cliche, its always the personality, Look at Zidane, he cant be anymore than 19 at the oldest and thats being generous, and yet, He's more likable than Squall, whose 17 as stated in the player manual.
Lets also take Tidus for example, hes also 17, everyone knows Tidus for him have two qualities, his terrible Voice acting, and that he hates his dad, okay that makes sense. Lets take away the VO, and make all the dialogue in chat windows like previous ones, hmm, now he doesnt seem so annoying right?
I use to hate X, but when I gave it a second chance, I really enjoyed it, havent beaten it, but we all know how it ends. Tidus changed in a way that was human, he would fuck up and be like "Holy shit, I'm sorry, I...I didnt know." My favorite part of Tidus was actually when he was moody, because it showed more than his optimistic zealous side and let us see his thoughts and feeling as he really felt.
ON THE OTHER HAND, Yuna is a character I hate, sees boring, monotone, and completely unlikable, what tidus sees in her? Hell if I know. Though story wise everyone is like, yeah, she changes, Im looking at her and think, No, she didnt. same for Lightning, Whats up her ass all the time? Ugh I gave up on XIII because the only thing keeping me playing was Sazh, The most Human character, and I barely got to play as him.
Im done ranting, good bye