MDM Workflow doubts

Step 1 : User "Creater" created workflow for table customer which has one stage "Approve" and approver user name is "approver"

Step 2 : User "data1" added a record in customer database. I can see Workflow status in the workflow pane as "Unlaunched". Is it neccary to launch for each record which you added?

Step 3 : Since workflow owner is "Creater", only "Creater" can lanunch the workflow or any other user can launch the workflow? Can I lauch workflow from API ?

Step 4: Once Creater launch workflow,approver can approve the record.Once,approver say "Done", workflow will be completed and nothing can see in workflow pane. How to take only workflow completed records through webdynpro frontend?