More people credit Kawazu for the actual gameplay/battle aspects of that game. FFIII is kinda considered Tanaka's baby, just like FFIV is considered Tokita's baby.
And yes, he HAS done more good with the FF series than he has done bad. While him talking about doing a new project has no ties to FF, I wouldn't mind seeing him collab with Square, if anything, on a new FF project. Right now, all things considering, I think he, Itou(where ever the hell he is), Tokita(who sadly prefers smaller projects) and Tabata are the ones who can do good with the FF series. IMO, Toriyama and Kitase are beyond help. Nomura's got FFXV to prove whether he'll sink or swim. Matsuno(not the FFT/XII one, but the ARR FFXIV 2.0 one) might also be in the running if he has the capability to make good offline FFs(I DO love the fact he spruced up the looks of FFXIV's world and added more nods to the series in general, so he knows his FF stuff).
Here's what I think of some of them:
Currently in Square
Yoshinori Kitase - I feel that he's got brainwashed by Toriyama, because I really like all of his previous involvement prior to XIII. The likes of CT, FFVI, FFVII, FFVIII and FFX. If he's more hands-on for his next FF, I don't mind seeing him direct one.
Motomu Toriyama - Outside of his work in FFVII and FFX, I really don't want him to touch another mainline FF. Never again.
Tetsuya Nomura - He definitely needs to prove himself with FFXV. I am a little apprehensive if he would deliver, but still am greatly looking forward to the game. Don't think he will direct FFXVI though, since he'll still need to helm KH3 and then a much needed rest.
Hajime Tabata - Crisis Core and Type-0 was a good run. If FFXV turns out good, I would give him a green light to direct FFXVI. But he needs more experience as he goes.
Takashi Tokita - I feel that he's stuck making ports and smaller projects. Not sure if he's even interested in mainline FF.
Hiroyuki Ito - Definitely the most suitable and experienced candidate to direct FFXVI. His history speaks of his capabilities.
Naoki Yoshida - Doubt he's leaving FFXIV and proceed to make a offline FF.
Akihiko Matsui - Same as Yoshida.
Hiroshi Minagawa - He's usually an art director, but I can see him making a good FF too.
Jun Akiyama - I feel that his young man deserves a chance to helm greater roles.
Tomoya Asano - Bravely Default was awesome. If he's interested to direct FFXVI, I am all for it.
Wild card
Yasumi Matsuno - I think he can solo direct a FF with some help, such as Ito. Ito handle gameplay, Matsuno handle story.
Hiromichi Tanaka - Would be interesting to see what he can bring to the table.
Hironobu Sakaguchi - I would like a Gooch FF again, even with him as Producer.