If you're not joking about the 500:1 leverage part (I know it exists) then you too have balls of steel; you have to be hedging at that point because if you're going in Naked might as well join mgrunin.
Not joking, CFD's are ridiculously leveraged. It's fine with sound risk management, even at 500:1.
edit: you think I'm trolling, here's one broker that does it
http://www.cmcmarkets.com.au/en/forex/what-is-fx-trading/advantages-of-fx-trading
An example of how I would use it safely is to have $20,000 of real cash in my account
I would buy 1 currency contract which costs $100,000.
That requires an insanely mere $200 margin (real cash) in my account. Far below the $20,000 I have in my account.
A stop loss would be set at 2% of my actual $20,000 capital,
not 2% of $100,000. So about $400 is the maximum loss I would tolerate. If the currency moves against my position and the value of what I'm holding goes below $99,600, it will automatically sell at a loss of $400 as I have prepared for.
The beauty of this approach is if one can trade profitably at this level, it becomes trivial to increase the number of currency contracts to millions of dollars worth.
If I was stupid and managed to lose my entire capital on a bad trade, lets say the AUDUSD drops 20%+ in one day (extremely unlikely, it took months for this to happen even during 2008) and I didn't have a stop loss set, I would be margin called at this point because my loss is beginning to exceed my account capital. The broker will sell me out of my position ASAP and any difference that is left I will owe them.
You don't have to be right all the time to trade profitably, that has to be the biggest misconception of any beginner. A 50% win rate is fine as long as your winners are bigger than your losers. That is possible with simple exit strategies. If a trade goes bad you follow your rules and cut it early. If a trade is going good you let it keep going good until it tells you otherwise. It will tell you when the price starts reversing.
Respond to the market, don't try to predict it. Unless you have a crystal ball or a time machine you're wasting your fucking time.