I am no magician but did you try to use the SQL Editor to query the table WorkflowProfileHierarchy. You will find the ProfileName there as a field. I have never tested it as it seems dirty, but technically that could work. Can you give me a feedback on that… I am curious.
I do not know how to change WF names from BR. (I think you can not)
There is currently not a supported BRApi that will enable you to rename a workflow via a business rule. I would suggest creating an enhancement for this as it would be nice to be able to both create a workflow and update a workflow's name via BRApi in a business rule.