B school always asks that question too, "comprehensive"? We all make decisions based on incomplete information, which is known at the decision point. Comprehensive means that you wish to hold someone/something else responsible, should the outcome not go as anticipated.
In Finance classes, we usually say that the "risk free" interest rates are found in Savings Bank accounts, and that's why they offer mere appitances instead of the riskier trading vehicles (Mutuals, CD's, etc.).
Simiilarly, your desire to become a Jedi Knight from jump street will lead you down the dark side of losses upon losses, just like the other commentator said, who struggled to find anything positive to reply to your naive questions.
Scalping requires in the absolute, the fastest internet connection available in your city. T1, T3, dedicated SDSL or similar. Then, it also requires the fastest processors that you can afford, generally 1.7Ghz and above or dual processor machines. Then it requires limited applications being open other than the trading platform, namely no browsers (IE, NSCP, etc.) or other comm programs (Instant msgrs, etc.) so that the full weight of the machine concentrates on quote/chart/banner updates. then it also requires nerves of steel.
There's an expression that says, the best way to make a lot of money is to start from a lot of money. This certainly applies to your ideal trading method.