This is part of the reason for dividing assets roughly evenly between cash reserve (30%), trading account (30%), and retirement portfolio (40%). There is still the option to "go big or go home," as you suggest, in the event of an unusually good opportunity. I have considered a larger allocation to the trading account, and might do so in the future. However, I experienced an account wipe-out in 2008 that makes me far more cautious today. Also, as I noted earlier, the downside (having to get a job) means much more than the upside (buying a nicer car, staying in better hotels). I'm no longer at the stage of aiming for the stars, just want to maintain freedom.
Yeah, I think your allocation makes sense.
Those kinds of historical sell-offs are a humbling experience, and right after that are once in a lifetime opportunities. The key for everyone is surviving those first I guess. For myself, one of my best winning trades have been the ones I took a huge beating on first. I agree, I think having financial independence should be the first goal before considering anything higher. This forces me to retain a very conservative portfolio myself for the most parts. I often take only retained profits from winning trades to bet on riskier high beta names, and it is these positions that often generate the better or a significant portion of the overall returns. Even though I also know I can put 100% capital on these high beta trades within a portfolio, it just doesn't make sense given my aversion to risk, to put it all in one basket -- to refer back to your point about splitting assets to cash and retirement account (probably buy and hold market ETFs).