Rob,
Pretty good track. I think the key to this music, after the writing part, is the arrangement, or if you are a classical purist, orchestration:) We called it all arranging at Berklee.. That is really part of the "mixing" process for orchestral music. In this case the music is interesting, you don't have things stepping over each other and everything is balanced well. The parts all mesh well together but sonically and musically. Your samples sound convincing, your stage representation is good (panning). Personally I really like the EW stuff and it needs very little processing. If anything it can be a little bright.
If you want some ideas, I would focus on two areas, 1) Reverb or space - you want everything to sound like it is all together in a hall or soundstage. To achieve this you may play around with adding reverb to your master bus to simply add a common sound that places everything in the same space. It sounds like you are using the stock EW sounds so a little reverb/space on the Master bus can go a long way. 2) Low end - These days with the cinematic stuff, people like to have low rumbling effects. If you have Waves Low Air or something similar, you might try adding a little bit to your low strings, percussion/timpani, or sound effects to bring some of that low-end dynamic to your track.
All in all it is very good and these ideas above are just window dressing to an already good track. Hope some of this is helpful.
Regards