"Stealing the show" is one of the main reasons for the lash against Xion, so getting it right definitely involves , as you said, a delicate balance.
I don't think heavy exposure to "make up for lost time" is a good idea, ever, for any character.
Maybe it's just me, but I really don't think it would be that difficult of a balance to do?
I know this is the KH writers we're talking about--and they're mediocre at best, so I shouldn't get my hopes up--but why not put her with character who also need development (that it would make sense she would interact with), and have them all develop some that way?
For instance, this is one of my favorite fan-made KHIII scenarios I've ever seen. It just speaks to me for some reason, and I can never stop thinking about it.
(By Axelxlea from deviantArt
Axelxlea (Lew) - DeviantArt):
Why I think something like this would be good is because... From Naminé's side, she used to be jealous of Kairi. So much so that she replaced her in Sora's memories. So Naminé reaching a place where she'd lovingly sacrifice herself for Kairi (even after just being revived in KHIII, no less) would be good development on her part.
And likewise, this is good development for Kairi. Because should such a situation happen, it would probably mean that the two have met again, and been given the chance to bond and truly come to love each other. In this image, Kairi's clearly devastated about Naminé trying to sacrifice herself for her, and will probably try to do anything to save her/stop it--with her being more active for a change, by perhaps reflecting on how much she hates to be powerless and how often that happens to her.
And if something like this were to happen, we might actually pass the Bechdel Test for once.
I just think it could be a neat idea, but it's only an example.
...
Btw, what do people here think of the Kairinort idea? Basically, it's going around on Tumblr that Kairi could be a Xehanort... because when her body was just left there and without a heart in KHI, Xehanort easily could have put his heart into her to make her a vessel. And I know most people would say that that's impossible, because she's a Princess of Heart and has no darkness for Xehanort to rely on to be able to do that. But at that time, she didn't have her heart at the time that would have
made such a thing impossible, but was rather vulnerable--so I think it's very possible Xehanort could've done this. It won't happen in a million years, but I kind of wish that it would.
...
Oh, and since I talked about this earlier in the thread, I'll post a similar picture I've found to the idea (another one by Axelxlea).
I really think this should happen/should've happened, even if it just ends with Kairi saying that she does love Sora and wants to be with him forever... but not romantically, and that maybe she doesn't even think she can feel that way for anyone (as KH-Info-Block said on their Tumblr), which would be one of the most mature things this series has ever done.
...
And on a less serious note... This has nothing to do with Kairi herself and her role, really, but I'm really hoping that we get a Neverland episode in KHIII, with her and the gang learning how to fly. Forget everything in this thread, but just give me that and I'll be happy
Kidding.
But no, I really would like that scene. But tbh, I think Nomura forgot about it long ago...
Edit: I also apologize for all the pictures I've been posting lately. If it seems out of place to anyone, I'll stop. But when I find things close to what I recently talked about in this forum, I can't help but post them.. seeing as how a picture's worth a thousand words, and all that.
And I'm also hoping Square Enix might browse this thread, and see in a passing glance that there are things they can do with Kairi. But yeah: if it's getting out of hand or bothering anyone, I'll stop.