help with denim and tailoring?

I recently bought a pair of nudie jeans that are a sharp bengt model and say anniversary wash but they do not even look like if they have any sort pre whiskers because they look and feel brand new and are stiff and I was wondering if I were to wear them like raw denim with out washing would I get the same effect. I also want to tailor them but nudie always has a orange/goldish stitching going down the inseam I would like to get them tappered from the inseam because I would like to keep the chain stitching but I don't want to risk the crotch having some type of problem becaus of tailoring them from the inside. what would be a good way to get them tailored and still get a good tapper