So I bought the limited edition of this back on PS3. Mostly for the soundtrack which is amazing, but there was one thing missing which is what I'm asking about:

Does the digital soundtrack here include Bang's super music?

I will literally buy this game now if that is the case (also if only just to have a copy again since I sold the actual game after I got Continuum Shift. Would be nice to have.)

If you are refering to the INSTRUMENTAL theme, yes is included
Gale: http://www.youtube.com/watch?v=UqHqLE9i4MM

but you are refering to this song, sorry is NOT included:
"Omae no Tetsui ni Kugi wo Ute" by "Hironobu Kagueyama" :
http://www.youtube.com/watch?v=swUeHhBVjko

there is NO VOCAL songs included, only instumental.... sorry

That lyrical one sounds slightly different than the one that I'm used to for some reason. It has a definitive end that doesn't involve "SUPAH CRASH", is shorter, and doesn't include as much instrumentation. Vocals sound a bit different, but it is also higher quality. Pretty sure the one that I have was ripped from the in-game track player.

Here's a link to the version with which I am more familiar:
http://www.youtube.com/watch?v=eGW8L61KzAU