This is fantastic! I can really tell you've been absorbing a lot from the forums. Your mixdown is almost perfect - my only point to mention is that your piano is a bit overcompresssed and can be a bit loud in the mix at points.

Beyond that, I'm seriously stunned at the production on this track - I can't wait to hear the finished product!

edit: also, hope you don't mind that I moved it to the WIPs section. I know you're asking about mixing advice, but it's my job to help prevent confusion about stuff like this, so people don't just post their songs anywhere instead of in the designated areas.