The reason that you don't get a response from someone at Gretsch/FMIC to the questions that you have about the construction of a Gretsch guitar in the United States is that those questions don't lend themselves to an easy, quick answer. They are complex, multi-faceted questions that require considerable nuanced analysis and consideration. In addition, I can well imagine that, in order to offer you a well-considered response, it might require the disclosure of information which is confidential business data and details that the company isn't keen on having out in the public domain for competitors to learn from.
But, this question has been discussed frequently and at great length over at The Gretsch Pages (www.gretschpages.com
) by some well-informed and smart people. I would recommend that you head on over there and take a look at some of the historical threads that have talked about this topic, or create a new thread of your own and pose your questions there.
As for the Tim Armstrong model, most of the people whom I know who have actually played the guitar, including Duane Eddy (the legendary King of Twang himself, and member of the RRHOF), have found the guitar to be a very good guitar and an excellent value. I would encourage you to try to find one and give it a test drive. If you don't have any dealers in your area who carry one in stock, look to an online retailer with a generous return policy. In the States, Musicians Friend is known for its generous policy of allowing a guitar to be returned, within a reasonable period of time (I believe it may be thirty days) for virtually any reason, including just not liking the way the guitar plays or feels.
Good luck to you.