I was watching for such things in WTL, but frankly I wouldn't have recognized many such errors. I was just looking to see which guitars they were using, which they didn't let us see very well. But I think if I HAD noticed such errors, it would be more for my amusement than that it would have wrecked the movie for me.

Now, the wristwatch in a high school production of "Brigadoon" was a wee bit over the top. That was no little thing; anyone could have noticed it. Oh, and one of the principles was wearing Earth Shoes, too. Sheesh!

Frankly, I doubt if more than one viewer in a hundred (or even fewer) would notice the guitar nuances that you mention. However, in such a production, we DO have the right to expect that they would not make such mistakes. Avoiding them would surely take little effort compared to all the rest of the effort that went into making the movie. Heck, they could have logged onto Mudcat Cafe and gotten quick answers for free!