I’d add one thing to number 5: Writing good copy is crucial not just for your Title/snippet, but for your whole page, especially your landing page. You want people to stay on your page for a while and (hopefully) even navigate to other pages you have. Google looks at bounce rate and where they go after they hit your page. Learning to write good copy can not only increase conversion (if you’re selling something) but make your content more impactful and engaging. There are free books at most libraries or online to help.
Lastly, it's important to remember that paralysis by over-thinking is a real issue some struggle with. There's no pill for it (yet). Predicting perfection is a fool's errand. Get as close as you can within a reasonable timeframe, and prepare for future iteration. If you're traveling through your plan and determine a soft spot at any time, simply pivot. It's many hours of upfront work to get your strategy built, but it's not too hard to tweak as you go.