At first, I thought you were talking about technical skills, but you’re actually referring to psychological skills. Yes, along with proper technical skills, you also need to be mentally strong. Among the things mentioned by the OP, I believe risk management is the most crucial. One should assess their risk-taking capacity and open trades accordingly. In addition, you need to be cautious and prepared for unpredictable market movements.
If you are someone who practices proper risk management and analysis, then you have already done half the job. I personally prioritize risk management and stop-losses above everything else. Both have significantly helped me protect myself from market losses.
I have to agree on you. Having risk management is like your capital protection, and would prevent yourself from unpredictable market movements. You can be good in fundamental and technical analysis, or even patient with trading, but without proper risk management, the outcome of your trades will not meet your goals and expectations.
However, proper risk management develops through a gradual process. You don't get good on it instantly, you have to learn it from your series of mistakes and losses from trading.