Get your core stuff down. Writing is a natural ability that reading and school can enhance. Role-playing systems are more complex. Try your hand at DMing a game. Learn how and why something works.
Game design is the elusive one.
I learned what I know through many years of apprenticeship, I guess, working with other designers. It's not something you can really learn by critiquing other games. You have to learn from others and, ultimately, try to do it yourself. You will not get a job designing a game on desire to do so alone. There are at least one million people who would like to do this for a living, if the resumes that cross my desk are any indication.