You have nailed so many points that resonate with my own experience. Just one example, I spent 18 months blogging into a void till I saw some traction — lesson — blog about your passion else you have no chance of maintaining the pace. In business terms, a blog is a freak investment, it just keeps on giving.
Your reference to Hemingway sent me on a long trail of editor software. According to this final read, http://www.serenity-software.com/pages/notes_observations.html you are probably a good writer, period! Hemingway’s layout is probably good for your writing soul, rather than a grammar/style tool that makes a real difference?
It appears that all writing tools are spectacularly under-armed to cope with the vagaries of language. Word still seems to be the 800lb gorilla for spotting errors, but compared to human editing capabilities, it is still probably not even as smart as a real gorilla.