I pulled the latest source and was able to default "show author name" off with this key in my user.config:
<add key="Blog:ShowAuthorNameCheckedByDefault" value="false" />
I do appreciate having this control at the installation level for now. If you feel it's worthy, I still think a low-priority change tracker entry to promote these three keys to blog-level settings would be helpful for us. I'm pretty sure that for at least a few blogs on our library site, we'd like to be able to default some of those on. Definitely no rush though.
Jamie