Until you get over confident and ignore it, as in the starting of the thread. The issue here is not your "system", it is the ability to follow it. Let that sink in... The truth is, some systems are easier to follow than others. A lot of that is "fit" between the person, their risk-pain threshold, and the system. Right now it seems you are trying to use a system that does not fit your personal "style".
Very simple. Don't trade with high leverage. Trading with high leverage requires a massive edge/skillset at such a level that you wouldn't be on a forum asking for advice. High leverage = high risk of ruin. If you trade with low (er) leverage you can have less precision in your approach and even make money just by being lucky and holding as the market moves against you. Adding positions to a winning trade in a strong trend is also something you can utilize to make sure you maximize your winners while always keeping your losses small (full loss is on your smallest size). PS: This is not me preaching from my high horse. I've blown a few smaller accounts myself by trading with too high leverage - effectively being stopped out by noise and even being right on my trade thesis. PPS: If you trade with lower leverage it's much easier to cut your losses, too.
With your current experience/skillset as I understand it, I'd say yes. A smart trader once told me: "Small accounts seek volatility; large accounts seek predictability" Anyone can have a great run and make big money in a short (or longer) period of time, but they usually won't keep it. Very, very few can make big money consistently year in and year out. You just have to be honest with yourself and where you are. Putting your money greatly at risk (high leverage) without a very smart and tested plan to back it is just silly, unless you have a lot of money to take from and it's just play money. The market can be a brutal teacher, but it's important to also acknowledge that the market can't do anything to you as it's only ourselves who choose to participate and put our money at risk. I hope it all works out for you.
I don't know of any way to control the amount of leverage I use. The leverage is mandated by the brokerages or written into the contracts.
Sorry big big typo Year after year after year No!!!!!!!!!!!!!! Extremely remote for anyone to achieve 100% yearly ROI long term.