I think you are looking at all the correct categories so far but you MUST address trading Psychology. I have been a trader for 11 years and this was my biggest hurdle to overcome. This is a very dynamic subject as well since it varies so much from trader to trader but just keep in mind that you will spend most of your time here.
When many traders first start trading they have a free spirit and open mind, this in-turn usually puts them into the money until there looseness strangles them and they incur losses. This is the start of the quest to find the grail. During the whole searching process the mind is still badly hurt and fearful of taking on risk/not sure things. Even when a trader finds there edge they still have this bad psychological baggage and it is very tough to push past it. One of the key things to do is to regain your faith by reducing to the smallest size possible until you are in a free state of mind with your trading once again. At this point you have a trading strategy and a relaxed show me the money spirit! If size is not reduced and faith is not restored a crippling state of mind will set in and your process will continue in one large circle. Have a great day and hope this helps.