Well, first of all, debugging while developing an actor is actually easier: you just have to debug an actor in isolation and make sure it does the right thing and sends the right event in response to the incoming event.

In terms of debugging issues when in live, you have to rely on tracing and let something such as Logstash handle search, etc.

The ordering of the workflow is preserved. As I explained, FraudCheck is only ever done after an order's payment has been authorised.

Hope this makes sense.