dam:assetState is being set to processed in the DAM Update Asset Workflow Completed Step. Please check if you have that step in the dam update asset workflow.

Check the "What is service ranking" section of this article Adobe Experience Manager Help | Getting Started with Adobe Experience Manager and OSGi bundles

Check the jcr:createdBy property on the dam:Asset node.

You can use the Dynamic Participant Step. Adobe Experience Manager Help | Creating a custom Adobe Experience Manager Dynamic Participant stepAdd a user picker in the page properties for the author to choose the user/group and get this property in the dynamic participant step.