This already sounds great!!
The mix is as good a it is. I hear some choir like vocals and some vocal snippets, I hope they won't get in the way with the vocals you gonna record.
I like the piano chords but here's maybe an idea to bring more variation to them; you can make them really short, almost stabby in the breakdown and then add a small dub delay. But watch out to not make it a sonic mess. Just a little idea.
Dirk