Nice. I think mark-defun is going to work out per other comments here but this is interesting.
Related question... I've not done a ton of elisp hacking but can I ask how you found uot about these functions? I've never heard of the two key ones: eobp and current-indentation.
Thanks. In this case I'm not only working with Org Mode but I can at least dive into that function and see how it is accomplishing the task for Org.