Hi Maarten,
After 10 hours here is the best performing EA:
In this screenshot you can see the Stop Loss range and Take Profit range in dollars I selected. Then I clicked on Edit and then clicked on Report to see the stats.
Here are the stats:
Here you can see many statistics about this EA. I only boxed in one of the stats because you were worried about how to determine account risk. The boxed in stat shows that over the last one year of backtesting the worse case trade had a loss of 9.89%. So you could use this to set your account risk.
Here I have shown an example on how to use EA Studio to find some EAs for XAUUSD. Hope this helps to get you going!
Alan,