Man, all of this feedback is invaluable! Thank you guys so much. A lot of things to think about. Finding ways to "de-mechanize" the sound is something I need to focus on.
I think my main reason for leaving out reverb is that the built in reverb of BBCSO didn't sound too great, at least for this particular track. I was hearing more of a "slapback" delay/reverb rather than a nice, smooth reverb. It could be that I was simply using too much, or it just didn't fit right with the combination of mics I was using (Mix 2 + full spill). Either way, I will go back in and play around to see if I can make it sound right.
On that note, is there a good dedicated reverb plugin you guys could recommend?
I'm looking forward to making some changes to this piece to really bring it alive. As far as those moments of complete silence, I think I envisioned a soft sound of frothy waves in the background, but ultimately left that out because I thought it might be too cheesy. Something I've been doing (since purchasing BBCSO) is trying to adhere strictly to the size and distribution of the orchestra, mainly to train myself to use only what's there. But sometimes a piece requires 8 clarinets or double the strings, you know? I have to remind myself that there really aren't any rules; the point is to create compelling musical emotion.
I thank you again for the advice and encouragement!