Hi David,
A marvellous composition with a very decent use of VSL libraries. Fantastic! The sound setting looks OK to me, after all it's a chamber piece and doesn't require a huge ambience. I guess you've made a good choice of venue.
The only thing I'm missing a bit is energy. This work could have a lot. A more daring interpretation would - to my taste - add more value to the wonderful composition. I think of powerful sample starts, (sfz or the-like), precise choice of articulations, tempi, accents... Of course this is a matter of taste, but the piece could get a lot of benefit from it.
Congrats for the fine composition!
Max