Operational Risk related tasks. assigning an operational task to admin staff.

I need to draft a professional email to my manager about assigning an operational task to admin staff. These are the main points:
Asking the admin staff to access certain applications to generate VAT invoices sounds an operational task rather than an admin task. These are my concerns:
1- This may leads to an operational risk as:
a. the staff is not properly trained or doesn't have the required skills.
b. these invoices will be posted into the general ledger and if they are wrong; it will have an impact on the ledger of the company.
c. Do we have a procedural document for these operational tasks?
d. transferring tasks from function to function may lead to conflict of interest.
2- Accountability
a- Who will be responsible for the mistakes generated by the admin staff?
3- Backup
a- Who will be her backup during her absence.
4- Approval
a- Her line manager at GCS should be aware of and approve these tasks.
Thanks and Regards,
Wael