Don't mind the idea of sequels one bit as long as the story in XV doesn't feel purposely incomplete. I liked X-2 a lot, and X had a definitive ending, though it did leave a few questions unanswered. If they can come up with a good justification to revisit the XV world, and make it a solid game, I am on board (assuming XV is good, of course).
Also, I don't care if this game has any playable females. I am female, and I wouldn't care at all if all the playable characters are dudes. The way I see it, if Nomura thinks Noctis' group having all guys makes the most sense and feels the most natural, I'd prefer that than having females shoved in and feel forced just for the sake of having the token chick. Noctis having all close male friends makes sense. And from what I've seen Stella still seems important and interesting and she seems to be an antagonist which is interesting. And she can fight. I had no problem with X-2's all female cast. It felt natural, the chemistry between a group of female friends.
Man, I'm trying so hard to keep my hype in check, but I really want this FF to be good. Nomura seems like he's trying to make the game as ambitious as possible and I do like him. If he wants the more powerful hardware to make the game better, not just flashier, I can accept that. The car driving sounds awesome, and it's good to hear he decided to keep the scope of the game intact, rather than cut stuff. If the game turns out feeling next-gen along with keeping the scope in line with at least XII, the long development time will be worth it IMO.