It is all pretty subjective . . .
1. I don't think Garden City, Myopia, and NGLA should be lumped together. Garden City and Myopia were built pre-1900, and while they both reportedly morphed into very good courses, I am not so sure they started out this way. Plus, they were both very different types of courses. Even the changes and improvements at Garden City and Myopia focused on difficulty, whereas NGLA was the wholesale application of the fundamental links golf principles in America, and its impact was truly revolutionary (arguably, even on the two other courses you group with it.)
I would say that the first three good 18 hole course in America were Chicago Golf Club, Myopia, and Garden City. I think Chicago, Myopia, and Garden City were considered the best in America but they were not considered great on an international scale. In contrast, NGLA was considered World Class, America's first truly great golf course, and one on equal footing with great courses abroad.
If you want to avoid the good/great discussion, then I think it would be reasonable to say that NGLA was the first course in America wholely based on the underlying strategic principles of the great holes abroad.
2. ANGC may have been built for spectacular golf, but like another above, I am not sure it was the first course built for spectacular golf. CPC seems pretty spectacular. The setting was certainly a factor at Pebble. Even NGLA was chosen in part at least for the spectacular setting. In fact one could argue that just about the only thing that the very early version of Shinnecock had going for it was its spectacular setting near the Ocean.
3. Not sure I understand the significance of some of the categories, like "first great Monterey course."
4. I don't know much about The Golf Club, could you briefly describe it and its influence?
5. I agree that Sand Hills was a very importnat course. I view Bandon as important because it took the great land combined with minimalist concept and applied it outside the private course setting. It is one thing to convince a few hundred people to support a club, but quite another to survive as an out of the way public. Although it is arguable, I view I view Rustic similarly in that it proved that understated but sophisticated minimalist architecture could succeed even at the lower end of the price scale. I haven't played it but Wild Horse may fit in this category as well.
6. I don't know that Augusta was built to be a major tournament course or if that was more of a plan to generate interest in the course (and the hotel employing Jones) I'd say its major impact though has come with its television exposure, but that impact hasn't necessarily been a good thing for golf.
Like I said it is all pretty subjective.