I can't confirm as I don't have it, but I think these days with physical versions you usually get a steam key so you can just stick that into steam anyway and there is no need for the disc, so you may be okay without having a DVD drive.
Most definitely normally the case. But they actually have separate digital and physical versions (Digital is a tenner more!) and people specifically confirmed this in the Q&A section. It looks to me like the physical version does not have a steam key.