Is there any integration to update local csv submission file?

3) Do you have any integrations that will auto update a csv file located locally here?

We do not have an option to update a local report file, but this is possible to download a report file by accessing a special report link.

How to create an Excel/CSV Report

Also, we have an option to automatically receive form entries in Google Spreadsheet.

How to Integrate Form with Google Spreadsheet

If you need any further assistance, please let us know.