You cannot edit calculated members, because these values do not reside in the database.
You cannot edit attribute dimensions, because these values do not reside in the database.
Dimensions composed of implied shares (or user-defined hierarchies) aggregate differently than conventional dimension hierarchies. Therefore, the implied share may overwrite data edits made to the Parent of an implied share as the model is pivoted.
Example: Actual and Budget are implied shares of the Parent, Scenario. Scenario, however, is a categorical label, not an aggregation of Actual and Budget measures.