Search for NT Service on the forum and you can give SQL permissions for a directory of choice if you want somewhere specific.
You manually add SQL service - should look something like NT Service\MSSQL$SAMBAPOS and give full access.
The database module is using SQL to backup. It’s just a UI access to it. It’s doing the same operation that MSSMS would do except it’s also zipping the backup to save space.
No simple way to do this.
Provided similar versions it should be posible using sql managment to restore specific tables but allot of potential issues depending on how much has been changed in 4 years…
If by records you just mean your list of customer entities that wouldn’t be so bad.
If you want to keep sales data its a little more complex.