Kill the bools

This is a huge pull request -- and will get bigger. Creating the request so we can easily track it, and the issues it resolves.

Closes #124: Cleans up our use of critical/debug/warning
These exceptions are already `aws.sqs.<Exception Name>` so I think there's no need to prepend it with "SQS" and "Exception" string, just `aws.sqs.QueueNotFound`