Re the Kingdom Ministry to Kingdom Service and back to Kingdom Ministry, this had to do with the influence of Ray Franz in the 1970s. During this rare period of reasonableness that he brought to the GB, it was decided that "service" was a more encompassing term than "ministry," as it could include acts of kindness and helpfulness. He also promoted the concept of an "internal ministry." All this could be covered by the word "service." This gained enough traction that "Our Kingdom Service" became the new title.
Then, when Ray was removed, dismissed from the Bethel Family and subsequently disfellowshipped (or as it was mis-described "disassociated"), what reasonableness he contributed was suspended in favor of a "tightening up." It was in this process that the title, "Our Kingdom Ministry" was restored. It was evident that the GB was attempting to undo every bit of work Ray had contributed while serving in the Organization.