(1) Game length is very important -- what many times prevents a "good" game from being a "great" game is length and the ability to sustain player interest throughout the entire duration of the experience. In the FF series, the former is typically not an issue; the latter, however, is sometimes a concern. Character development is one area that, when done exceptionally well, can cause a game to truly excel. My hope is that Crisis Core has the character development and story to live up to the precedent set by FFVII. New game play aspects would be nice, if well implemented, but I wouldn't object to sticking to the ol' tried-and-true RPG formula.
(2) I would, without question, buy a FFVII remake for the PS3. It is one of a few games that, I think, actually warrants a remake for those who didn't get the opportunity to play it the first time around.
(3) Great games have always been about the story, and for RPGs, this cannot be more true. Great graphics, game play, etc., will always be relegated to the back seat -- a complementary role -- compared to the story. Particularly in the FF series, I hope that they always first make sure they have a solid story that stands by itself, that doesn't need to be propped up with flashy graphics or gimmicks.