Interesting take on this style... Maybe a bit in the vein of Copland's Appalachian Spring, as orchestrated for a band. Nice feeling to it.
Just my 2 cents: harmony wise, was it all planned to have semi-naked chord progressions? I mean it could be naked in the beginning, and then one could have used a harmony growing in complexity and completeness to generate an emotional climax, so as to complement your orchestration at the end with the timpanis and all... I will attempt to clarify my thoughts here by sending an example score, when I have the time...