Nomura's team had to help develop FFXIII-2, Lightning returns, and FFXIV: A Realm Reborn, which all delayed the development of FFvXIII. This is not Nomura's fault.

This isn't really suprising me, as after this long development time, i think they changed many more things from the original concept

This is the same guy that directed the mediocre Crisis Core. What can you expect?

I like Tabata, even though I haven't played a single one of his games, I think his very open-minded and able to take constructive criticism seriously, but, FUCK, man, Nomura was the creative soul behind this game, without him, I fear that all those epic moments and set-pieces that the game was "obviously" going to have might be done sloppely, I mean, the Demo it's already a BIG fucking downgrade from the E3 2013 trailer, the camera is worse, no, no worse, it's the fucking worst, the combat looks slower and far more sluggish, set-pieces like the first encounter with the Behemot/Behemouth/Behe-monsterlikecreatureoffinalfantasy feels tagged on and it's just FUCKING BORING man, the only way I can see Tabata's FFXV being "exciting" is through cutscenes.

I think that the whole team behind FFXV suffered by the main programmer leaving, and Nomura too in favor for KH3, because everything seems to have been crapped on since they left.

You don't understand my statement. I dislike Tabata for changing it, because it is his say as director.

I just know. I'm good at these things. Believe it!

Dude, Nomura was removed from FF15 and even released a message about how it left a burning anger that he was gonna channel into KH3 for his best ever game blah blah blah. 

Hell, SE even released a statement that tried to downplay Nomura's involvement as just a orginal concept guy, to lessen to impact of the announcement. 

im also sad to see that they took out Stella, i may not have seen her even talk or interact with the other characters but i really liked her role on the story, the whole deal of having (as you said):

"a pretty cool protag and an evenly strong, contrasting female protag, all with supposedly strong romeo/juliet influences"

was one of the things that most interested me about the game.

im very surprised to learn that the story isnt even finished at this point or that they are still changing it, when i assumed that at this point that would be something done and set in stone.

You know, most of the time, it wasn't Nomura's fault that the game was kept  from being worked on, it was mostly the fact that Nomura's team had to help Square with a lot more projects than just Versus, since Versus was just an exclusive spin-off, Square took priority in their main tittles, basically leaving Nomura saying "well, fuck man, what the hell do I do now? Wait, I have KH! I can do more games there while my main team is busy." 

The only thing we can really blame Nomura for is for him being so fucking secretive about the project, now because of that the "Versus to XV" situation is extremely confusing to most people, leaving people just to blame "big" names in Square because that's the easy thing to do.

I know dude! In FFvXIII, you could switch characters to Prompto Argentum, and shoot enemies.