can I default the employee for the discrete job and make one of them schedule

I need to create a Discrete job

1 - can I default the employee to the job and the actual duration during start the discrete job, I mean when complete the dob the employee names and duration will be defaulted

2 - is there any standard report to check the duration of the discrete job based on the employee schedule

3 - in case I do not want to default the employee. how can I enter the employee during the complete the job

4 - Can I enter the employee for the job after completion?