Being comfortable isn't the way to learn to expand your abilities.
I had been writing fiction since I was in eighth grade, because I loved it.
Much of what we do in life has a huge component of luck.
What I look for in any character, good or bad, is whether I can hear him speak. If I can imagine him that clearly, then I can write about him.
I do like to explore evil characters in my books.
I do have to earn a living, so I'm conscious of probable reactions from readers, but the most important one is still the awareness that if I'm not enjoying a story, the reader won't either.