Is there any way I can specify in the bpmn that a set of user tasks should be assigned the same user. So if I assign the first task to user kermit, the other tasks are automatically assigned to kermit as well?
Create a task listener in first task on "complete" event, get the bpm_assignee & assign it to a variable. Then create task listeners in each other tasks on "create" event set that variable back to bpm_assignee.
No, pools and swimlanes don't have 'memory'. In bpmn, they are merely for documentation.
You could have a 'low-cost' solution by doing something like vkajamugan mentions, but using a ParseHandler (although it will be applied always in that case …)