Music Composers Unite!
You're so close to having a really good sounding piece but rather than me telling you what you need to do to improve on it may I simply say, trust your own ears. solo each section and track. Close your eyes and ask yourself, does this instrument sound believable? Is it close enough or far enough away from me the listener compared to the other members of the ensemble?
Are the flute runs realistic or should there be some slur in there?
All I'm saying is, the degree to which you are willing to go in achieving your goal is down to you.
Listen to recordings made of the same genre until you can hear and place the instruments in your head. Then use that as your guide.