When mitigating relevant financial relationships, should I be using different approaches for planners, authors, speakers, etc.?

Yes, most likely!  Many of the mechanisms employed to mitigate the relevant financial relationships for authors and speakers do not directly address the planners’ roles (specifically, in controlling decisions before content is even developed).  Providers should have mechanisms in place that directly address the planners’ unique role in CE activity design.  For more information, the ACCME’s Toolkit dedicated to the Standards for Integrity and Independence in Accredited Continuing Education does a good job of addressing this.