What is the complete list of expected JSON responses for DS.RESTAdapter?

Instead of stabbing in the dark, have a look at rest-adapter-test

For example, to fill in your question on response data for bulk updates, L738 describes the expected response data:

ajaxHash.success({ people: [
  { id: 1, name: "Brohuda Brokatz" },
  { id: 2, name: "Brocarl Brolerche" }
]});