I feel somewhat guilty about this, but I thought sidetracking from the main story was one of the best things in the game. :p The world of FFXII was huge and had so many places and things to explore that they added a lot to the atmosphere of the game, which is just as important to me as character development. As for character development, I thought it was more subtle and happening throughout the game, as opposed to some of Nomura's FF titles, where there's plenty of melodramatic in-your-face character development and the character growing as a person in pretty much a single scene.
About the characters not getting much interaction and development, the script is 120-130 pages long if you don't include any of the NPC dialogue. Sure, that's not as much as FFs 7-9, but it still indicates that there is plenty of character interaction. To be frank, it's not like characters such as Cecil, Rosa, Kain, Rydia, Butz, Lenna, Faris, Galuf, Cara, Ramza or any of the characters from FF1-3 got much more development, and the character development for Squall, Rinoa, Tidus, Yuna, Wakka, Lightning, Snow and Hope felt a bit forced and sudden, IMHO. About FFXII having "useless" side characters, does anybody remember Edward, Palom, Porom, FuSoYa, Strago, Relm, Gau, Mog, Umaro, Gogo, Red XIII, Cait Sith, Vincent, Yuffie, Selphie, Irvine, Zell, Quistis, Eiko, Amarant, Quina, Lulu, Kimahri, Vanille, Agrias and Orlandu, to name a few? :p They had about as much development as FFXII's side characters, and I don't see anyone complaining about them.
On another note, I've beat FFV twice on SNES. The first time I played it, I didn't think the story was anything special. But when I played it again, I noticed how detailed the story and the characters actually are. Maybe it's the same way with FFXII, meaning you need to play it twice to get most of the storyline and characters?
Excuse me, but this definition sounds extremely questionable to me. For example, the first Final Fantasy game (FF, or FF1) had pretty much none of the things you described (plot, character and feelings, whatever the latter means), and yet it's one of the most FF-ish titles in the series. It has a medieval fantasy world, characters with classes (Fighter with a sword, White Mage, Black Mage etc), Bahamut, elves, dwarves and other species, and themes by Nobuo Uematsu. I do agree with the FFs not being the same without Uematsu, but admittedly, his role has been from small to none in every FF after IX (except Advent Children and FFXIV). At least FFXII brought back Prelude, Final Fantasy Main Theme (aka Prologue), Victory Fanfare, Chocobo Theme and (SPOILER)Clash on the Big Bridge. Out of these, only the Chocobo Theme is featured in FFs X, X-2 and XIII, and Prelude in FFX and FFXI.