Denormalization vs Child/Parent & Nesting
It's hard to denormalize your data. For example, the number of performers in an event is unknown; so if you were to have specific fields for performers, you would need perofrmer1.firstname, perofrmer1.lastname, performer2.firstname, performer2.lastname, etc. However if you use nested field instead, you would simply define a nested field Performer under event index with correct sub-field mappings, then you can add as many as you want to it. This will enable you to lookup event by performer or performer by event. The same apply to the rest of the indices.
As far as parent-child vs nested, parent-child provide more dependence as child documents reside on a completely separate index. Both parent-child and nested fields can specify "include_in_parent" option to automatically denormalize the fields for you