Can I use the same character name or book title as another novel?
I'm guessing the answer to #2 is yes, but I'm not sure about #1 and less sure about both factors combined.
I want to use the same character name(and probably book title as well...that's less important) as William Gibson's "Count Zero". I've never read it, and my story is a different genre than Sci Fi or Cyberpunk. More of a modern urban fantasy. Although, my character does use "Count Zero" as an alternate name/pseudonym/username/etc.
As some characters and even writers do. Particularly when interacting within/outside of a certain community.
to others: it's sort of like you write a character who chooses to go by "Tom Sawyer" or "Huck Finn" when using an online handle, or within a secret-ish group.