While I am also a big fan of Nobuo Uematsu's work, actually my only reference when doing this was Melody of Aqua (Sailing to the World) by Yasunori Mitsuda to get the feel and tempo up to around 1:27 of the music. What a coincidence, I am curious to know which FF7 music are you referring into? Maybe it could help me more.
I completely agree with you about the realism, I was like "How long does the flute player could play a composition like this?" Maybe I should try to change the middle to another woodwind like Oboe or strings like violin so he or she could rest a while and add a few holes.