Here are some answers:

copyObject error - we were using a Databricks provided cloudformation template but this error goes away when we use the AWS provided template

createWorkspace error - we had subscribed>unsubscribed>resubscribed to Databricks via the AWS Marketplace. This cause our Databricks account to get 'locked' in a Cancelled status. We simply signed up again under a different email and the cloudformation template launched without an issue.

All good...hope this helps out!