1. Is it possible to run another "write" job containing the same input parameters without creating duplicate records in the content repository database?
---> Yes you can run as many jobs as you can with the same variant , but records will only get stored into content repositories during store process, even though if you have multiple records in content repositories you wont get any duplicates because the records which is deleted during delete process is only accessible, so there will be no duplicates created.
2. If not, is there a process to delete the records that the canceled storage jobs created in the content repository? If so, can you provide me with the process documentation or tell me where I can look to find them?
--->There is no job for deleting records that were created during store process, you have to delete it manually at OS level but it is a risky process. but as i said earlier you wont able to access duplicates from archive.
