Re: 1., I’m personally unwilling to move outside the U.S. but agree it could make sense if you can make it work for you while maintaining a high salary.
Re: 2 and 3, I completely agree. I think in particular about longevity medicine as a potential future expense. You can certainly build up support for higher-than-current expense levels to address these risks. You might also retire to less profitable or more risky activities that you find more enjoyable (but that supply >0 income), or simply stay in your current profession—but with the advantage of having higher option value.
Skimming that link, I think it shows backtesting; have you actually beaten the index yourself with real money? For what time period / amount of assets?
I mostly avoided leverage in this post because I don’t use it and kind of don’t trust it. But if I had to give a better defense of avoiding it, it would be because 1. it’s really easy to lose a bunch of money if you use it wrong and 2. I’m not sure there’s a reliable way to borrow money at low enough rates to get good results. Most of what I’ve read about leverage pretends the interest rate is 0, which it’s not—looks like Robinhood offers 2.5%? What’s the most reliable interest rate people can get, and does this rate kill results?
Definitely agree not to discount bonds though; without leverage, small amounts give you large risk reductions for small reductions in growth. I personally am 100% stocks because I’m preferring to maximize (unleveraged) growth, and have decided I can tolerate the increase volatility over 10-20 year time spans.