Hi there,
Very nice and atmospheric images. I notice one thing though that's also visible in your former kitchen project. There's a clear white outline around the objects where you placed the background image. It looks like some bad alpha output and I also encouter this problem when saving out as .exr. I've done some tests and it works best if you tick the checkbox "direct visibility override" and leave it black. Now your alpha channel is o.k without losing your light setup.
OFFTOPIC:
If someone has a better workaround or some other info for better alpha channels when saving as .exr I'd really like to know.