Great points in a well-written presentation!
I would add that it’s easier to get closer to completely passive income in the very small and very large scale, while it’s much harder to do so in the middle.
On the small-scale side, you can e.g. create an evergreen-type digital product and sell it online. Sure, you can increase sales by putting in more marketing elbow-grease, but if you want, you can let it run on its own and it will likely continue bringing in small revenues almost forever (the more it’s really evergreen, the closer to forever you get).
On the large-scale end, once the business scales up enough, you can afford to hire people who will take over from you all the day-to-day grunt work. You should still make sure to oversee them at some level (as you said). It’s also helpful if you keep track of the market and figure out what strategic corrections/additions would be useful (again, as you said), but you can then hand off the actual execution to your trusted and highly competent employees.
In general though, I think the closest most of us can get to actual passive income is by investing in a diversified portfolio of market-index funds. It’s still important to make sure none of the funds’ managers go off the deep end, but that can be done with a few hours of reading a year.