Don't want to keep them on too long for risk of creasing and being unable to return them.I would wear them on the carpet for a bit and see how the fit feels after 30 minutes or so. I can't speak to sizing since G&G is so uncomfortable for me that I can't really wear them. I am sure G&G NYC can answer your sizing questions.
And yes, I emailed G&G to ask if they can offer some clarity as to what size the shoe actually is. I sent them a picture of the shoe, and the tongue so they can know exactly where I bought them so they can offer clarity.