Observations from DD's years in high school as well as what we've learned this first year in college:
a) Kids are NOT NOT NOT being well-prepared for college if they are earning A's in coursework that isn't difficult enough to cause them to truly scramble and learn good study skills,
b) Okay, assuming that you can engineer a transcript that is straight-A, worthy of a high degree of merit money, an elite admission, etc. etc. Does this student in particular have both the drive and the wherewithal (and no, I do not mean the cognitive power, but the OTHER skills like organization, work ethic, motivation, study skills) to make good on it at the next level?? Getting IN is one thing. Staying may be something else again. Higher expectations become a burden at some point.
c) Yes, transcripts are important in high school-- but not as important as the preparation for the launch during college. Your second point would argue for the more difficult coursework, IMO.
Don't think of high school as "the game of getting into the Best College Anywhere." Think of it as preparation for success at the Right College For This Student.
If your goal is an elite college and the proper credentialing from this point forward, then maybe learning to play the Tiger Game is a good move at this point-- and yeah, that entails near-perfect transcripts, and carefully groomed extracurriculars, test prep and superscoring, etc. etc. If that isn't your goal, then developing the best study skills with the greatest adaptability and variety possible is probably superior.
Caveat emptor.
