As the list of available actions is continuing to grow, could you please add a text field at the top of the 'Actions' panel that allows you to filter the actions being displayed.
For example, if you type 'anim' into the field, all actions with the string 'anim' in their title (and possibly in/under their internal variables and/or descriptions) would be displayed, potentially under their respective category headings (with unmatched category headings and actions filtered out).
When the user deletes the text in the filter field the Actions panel should return to displaying entire list of headings for all Action categories. An 'x' delete button should also be included to the right of the filter text field to allow it to be cleared by clicking on the 'x'.