I'm actually running an experiment much like this. In a year, I'll let you know how far I've gotten. The main difference is that I'm not day-trading, defined as being flat at the end of each RTH session. When I get into a trade, I never know how long I will hold it. I've got a very specific definition of a "trend" and I hold it as long as the "trend" remains in my favor. My average winner is about 7 ES points and the range is from a single tick up to 25 points. An average day is close to 4 points total. Sometimes I hold for a couple of hours, sometimes overnight. Sometimes I get stopped out with a profit and then re-enter because the "trend" resumes. If the ES is trading, I'm watching for trades. One of the main problems I will face as my size gets larger is that I sometimes will have a position, long or short, and a trade in the other direction will trigger and in my strategy that does not call for an exit of the pre-existing position, but an adding of a position in the opposite direction. In the ES, this means buying the non-active contract, which means terrible liquidity, especially overnight. That could end up being a limiting factor. That said, with a 7 point average winner, I can afford to give up a few ticks in order to size my position to what I want. This doesn't happen that often, though.
Agree that it is not for a new trader. That said, when you start with a small number of contracts, you are quickly either bust or playing with house money. Real money, of course, but house money. But, you've got to look at it as a marathon, not a sprint. You can't say "I'm going to add X number of contracts a day/week/month/whatever", you have to take what the market gives you. And, you have to understand the "why?" of your strategy, so that when a drawdown happens, you don't panic. I have a metaphysical certitude in my strategy, even though, like all strategies, it is subject to probabilities and the reason is because for each decision node within my strategy I understand EXACTLY why the decision I will be making is the optimal decision to make with the information available at the time of the decision. I'm at the point where breaking a rule is more frightening to me than losing money on a given trade. You know how they say you should trade as if you were being paid on how well you follow your rules, rather than your trade results? That's me.
Also, fortunately, I have other income that is quite sufficient for me to live on, so I can try this with very little overall lifestyle risk.