I feel like the meat of your post is in the "Refine. Test. Refine. Deploy" section that you glossed over. Everybody starts at (1); they may arrive at (2) with different levels of how much knowledge they've acquired. You're purporting that minimal should be acquired. At (3) is when you start to get in trouble because you don't always know what you don't know.

There is no right or wrong answer here I guess. It's just what aligns with your goals, how you've prioritized things and what makes you happy.