R98403|XJDE0021 and XJDE0022 is one method. Be careful though - you have to set the processing options up correctly or you can really screw stuff up quick.
There is a thread from several years ago which I helped with on here that talks about the different types of database and the different recommendations for refreshing CRP with PROD data.
Best to do some research using the "search" button.
All depends on your requirements.
I recently managed a PD to CRP copy on XE, where there were no needs for historical data, so the duration time and the required table space was 50% in the copied CRP vs the sourcece PROD (on XE)