PM03 will capture the individual service(s) with actual hours & with cost. PM02 will capture the cumulative work with cost.
Yes, Refurbishment order can be created with PM03 as well. PR & PO is common for PM02 as well as PM03. But GR will be done when you go for PM02 & Service Entry Sheet (SES) will be done in case of PM03. Again usage will refer my 1st paragraph.