Why can't you backtest prior to August? When you say "US30" do you mean the Dow 30? You could download years of historical data on that quite easily (such as Yahoo Finance, for example).

Your algorithm appears to use an (exponential) moving average crossovers to generate buy/sell signals. Yes, that is "simplicity itself." Maybe too simple. If you're going to do algorithmic trading, I suggest reading Ernie Chan's book, "Algorithmic Trading - Winning Strategies and Their Rationale".