Good read AA.. I think you have to draw the line between day trading (scalping) and full-time trading/investing - In my mind, if you have enough capital there's no reason why you can't invest in the markets full-time.

I think to do this consistently you'd have to be able to trade the long and the short, and be prepared to hold equities for whatever length of time makes sense fundamentally and technically (rather than having to close each trade off at the end of the day as day traders do)... Of course the downside of this means you'd have irregular cashflow.