The focus we all need to really have is one of maximizing personal freedom / flexibility. You want to be able to avoid personal switching costs at all times, and live below your means so you don't need a full-time job (hand cuffs). Also, having a skill like programming or design (+ contacts to get gigs) is huge is keeping your flexibility. The lack of programers seems to make this the golden age of software entrepreneur "careers" - where you can always fall back on that.
Currently, I'm in a bit of spot after a startup gone "meh" - a sale I don't benefit much from and where I put all my savings into. I'm not a programmer, but I'm learning fast (got my first gig), and I'm able to do his part time contracting thing to get through it to the next one.
I think you've covered why it's a good idea, but I wanted to add a warning - having an infinite runway may cripple you. It may take away from your sense of urgency and desperation, which in turn may lower your chances of ever landing a success. This may change the equation so you'd be better off being a normal employee, given your skillset and drive.