I think your antena wire running from the wingtip to the vertical may have something to do with that one.
I see you are using the Himax gear train (good choice). Have you considered using the C gearing like I mentioned? I think this will give you the amount of power you are looking for. I locate my battery all the way against the nose with an extension wire going back to the sc and rx. The plane should balance out on the spar at the fuse sides. Can you take a photo from the side?
If I am looking at the first pic correctly I think you need to turn your prop around too. It should face forward just like if it were mounted on the nose and you will reverse the motor direction.