It says "on-screen text" so I am quite sure it means subs and menus etc. I think they allow Japanese voice overs, though.
You are correct that Square Enix has not denied it, but if Square Enix is or was considering it - showing our demand is not wrong.
It doesn't need to delay the launch, which is possibly still a year ahead. The core development team and localization team work beside each other
Well, I think the idea Japanese audio track + voice track in local country + subtitles would be best. Afaik two audio tracks could fit as Tabata said.
Games like Fable 2 offered an English audio track for the German version as a DLC afterwards, since it didn't fit on the disc. FFXV could allow this, too of course
I believe the game is still about a year away from release and since main development is being handled in Japan and localization for e.g. Europe in London and the local PR HGs, I think it would not impact the core development that much.
I dont want to erase the Japanese voice track, but the other languagees would just be an option
As mentioned in the end of the article its yet unknown whether Square Enix made cuts in the game to get that USK 12 rating. The article just retells the ESRB's reasons.
The recruit a friend campaign will allow you to come back for a month afaik plus you get some rewards