What do you mean by state here?
This is usually done by pressing record, moving the playhead forward, changing 'display' to 'Hidden' in the Element inspector. This automatically creates keyframes and doesn't require JavaScript.
This definitely does need JavaScript, and it's something we want to support in a future release 
-- Here's sample code: Creating Play & Pause Buttons for Video
Here's video showing how to morph between shapes:
A morph creates a 'path' animation, so this could be created on its own timeline. Then the additional timeline can be triggered as a 'mouse click' action (all without any code). Hope this helps!