please accept my humble apology for late reply.
Agile swimlanes in Scrum and Kanban remembers last settings. So, if you will leave this page with "Priority" swimlane set, same swimlane will be displayed when you open same page again. This default behavior cannot be changed, unfortunately.
Allowed status transitions you can manage in workflow settings in More>Administration>Workflow in Task status transitions tab. There you can set which status will be available to change.
https://documentation.easyredmine.com/easy_knowledge_stories/37 - easyredmine application guide
https://documentation.easyproject.com/easy_knowledge_stories/6 - easyproject application guide