@Calendee I too have a similar question here. As per your example I have added my-modal.html script within Index.html and it is working fine #fiddle1 
Now I am trying to keep it within an template my-modal.html like I mentioned in my question and here the my-modal.html not working #fiddle2 
As per the error in console, I can understand that I missing to point the $scope and therefore it is not working. But I am unable to fix it up. Please let me know your suggestions.
Thanks,
Praveen