The characters you refer to as predatory and unsavory are useful. They're the ones who make a novel into a thriller. They're active, and most of the common virtues, the signs of a good person, are not.
I do like to explore evil characters in my books.
I do try not to spend much time reading in the suspense genre.
I don't consciously do anything to maintain a unique voice.
Yes, in my books I do edit myself to keep from becoming the Village Explainer.
I don't have dry seasons, because I don't allow them.