Yes, having the sleeves shortened is a viable option. I'd go to a Neiman Marcus or other retailer where they sell high-end British and Italian shirts (which often come in a very restricted selection of sleeve lengths) and have them do the alteration there: they'll have plenty of experience, and it should turn out well. It should cost you about $15.
Absolutely, go to Neimans, they have experience from having to adjust customers' RTW T&A shirts. I think the price is $10 per sleeve, and the pleats come out better than before. Funny story; I once took a few T&A shirts to have the sleeves lengthened by a local seamstress who my mother's friends swore by (Metropolitan Tailoring in Birmingham, Michigan). The woman there first argued with me that it couldn't be done, finally conceding that it could be when I showed her the extra inch or so of material under the cuff. When I picked them up, she was actually angry over how "difficult" the work was, had not bothered to redo the pleats, and had allowed dark threads to get trapped between the material of the white cuffs . . . and on top of that, tried to charge me double what other places had done it for. What an experience and a lesson well learned.