Markdown syntax highlighting and rendering issues

There seems to be some issues with the note editor. See the following example which exposes a few of them:

• It seems that ":" has triggered some highlighting scheme by mistake. AFAIK, ":" isn't a special character in markdown unless it's in a table to specify aliignment
• An email address at the end of a line seems to cause the next bullet point to be colored green
• Nested list seems to be limited to 2 layers only

By the way, is there a way to exit the editing mode and see the rendering results without existing the current page and re-enter it?