Regarding your first intermittent task failure, could you post the task log? Does the task fail in the same spot in the load script each time, or is does task fail in random spots?
Regarding the second intermittent task failure, is there an error in the task log? In the SAP connector log? If so, can you post them?
Also, suggest you reach out to Qlik Support for further assistance in troubleshooting these intermittent task failures.