I agree, it should be 1 and 4 (update specific value and update record type). You cannot update the value of the child object using Workflow. You can do that using Process Flow. Usign Workflow you can update the value of the parent field, if the parent and child has MD relationship
In the computerized world, workflow refers to the consistent activities done in a business. Workflow includes the processes, planning and scheduling, flow control and in-transit visibility. The processes include a group of procedures of work that continues over and over again. The planning and scheduling refers to the way in which these processes will occur. The flow control refers to the speed and control of the work.
The in-transit visibility refers to the work that is in progress. In Salesforce, if you want to know the workflow field update action, you can update the value of a field on a child object and apply a specific value to a field. A child object is one in which it can only be done if there is a parent object.