Can these be better expanded upon? I would like options for function, Types, namespaces, local variables, enums
They are a property of editor, Scintilla. You should investigate its capabilities. I don't know whether you can enhance the lexer's at all.
You can indeed enhance it's lexers and create your own too. The problem is just parsing C++ code which appears to have been successfully done in a more detailed manner by the symbol viewer window to the left of the screen.
lexer != parser :)