Is it mandatory to assign a task to responsible agents?

Hello Gurus,

Iam new to workflow and i have few questions . Iam implementing CATS on ECC6.0 and in the data entry profile i have given the task ID TS31000007,Now i want to assign this task to an agent,

1. Is it sufficient to assign possible agents to the task through PFTC so that all possible agents can execute the workitem.

2. Or is it mandatory to assign the task to responsible agents <b>also</b> through a rule.

3. If i make the task as a general task can the perosn who entered working time can also approve it .

Sriram