I always end up confused while trying to arrange this hell of a piece, thanks for the advice, I'll get it corrected whenever I have the time (semester exams on the way T_T)
EDIT: I don't really got the point you stated, and while searching a correct scale, I found that the F minor lydian scale fitted it
And I just took the time to read the bass again, it IS Eb. It's just really, really weird. I also reseached the whole tone scales, which I didn't know the existence of.