Refactor high-level API code

[gammaw]

E.g., rethink get_shows() method, see #143 (comment)

[pvj]

Meeting memo: Checked w/ @tuz666 this get_shows() util method has been implemented in #141 so I think the exact sub-task here has been resolved.

However, we do need to rewire high-level API functions and decompose them clearer so I would want to keep this open