None of us wants to be the one to tell you those parts are ok only to have you crash and come back later to tell us we were wrong.
Have you considered contacting Thomson to ask about your stem? Here is their contact page:
http://bikethomson.com/contact/ . Thomson has a good rep for customer service. I bet they'd respond.
I did look on Thomson's site for the topic of detecting crash damage. I couldn't find anything.