Hi Jeffrey,
qCalendarView web part's legend is at the list level not the event/appointment level. As a workaround you can use a qListView web part to display the colors on your calendar based on the event type.
Regarding the Custom Actions question, this is used to define custom buttons in the toolbar or new options in the context menu. This would allow you to achieve even greater functionality of this web part (custom code, chain of actions, etc). Please check the documentation for more details.