I looked at the typora website and having a preview in the editor looks really cool.
The two requirements of "local asciidoc viewer that is aware of its own document root" might be covered by IntelliJ [community or ultimate edition] + the AsciiDoc plugin.
Editing has to be done in a text editor with syntax highlighting. Preview is separate.
What you'll get:
- Integration of Git
- The "document root" would be the folder that you open (usually also the Git root)
- AsciiDoc viewer - either source code only, side-by-side preview, or only preview.
(I'll probably be biased as the current maintainer of the plugin)