Ohhh, thats interesting about G84, trying to keep it under-wraps eh? lol... I wouldn't mind seeing an ultimate cut of both G54/84 w/ Raymond Burr in it if thats what you were planning on doing.
What i'd like to do is what Legacy_of_gamera did... except better quality (no offense). I wouldn't mind messing around and take my time on the music and spfx, and yes, I would trim down some of the action as well.
What I'd particulary do is...
-Keep the opening title themes (Toho Scope, and the Opening title music THAT SONG KICKS A$$!)
-Have the classic Ifukube music replacing some techno music
-Bring back Minya's original wail/cry
-All G's roars (Showa, early heisei, millennium)
-King Ghidorah's original roar (Although its a new hybrid of Ghidorah)
-Keep the Sum41 music where G vs. Zilla begins
-Add the original Mothra music
-Change the end title music from that techno happy crap to either something Ifukube or "We're All To Blame"
-Have all the G themes in the movie (well try to at least) I dunno about G's theme in Hedorah/Megalon tho lol... I mean, I know that I'd put Ifukubes whenever needed, and maybe Oshima's theme from (GxM, GxMG, SOS) once or so.
Any thoughts? or changes? this would be something fun I'd love to do.