Point 1 to 4 are the main cause of attraction of many traders toward Forex. But in point number 5 you said " fewer varriables to consider " you may be right but i think any thing that can effect the economy has also effect on the prices. There are hundreds of factors that can fact the price. So to be a good trader we should not ignore any factor. Although it is difficult but according to the situation we should judge the right thing that is effecting the market and should perform accordingly.