If the project is already up and running and you need just to "protect" it from being altered, I can manage that. I have built and worked on several back-offices, sales & agents management scripts and I know HOW a system like that should work. I suggest to create different categories of users, 1 admin, moderators & simple users. You will be the admin and will have the FULL control over the project and you will have access to the logs and if needed you can delete, update, create new users and new records.
About the daily backup, I'll need to take a look at your hosting provider's features, usually they offer this as a feature, if not there is the option of a cron job that runs periodically and backups everything.
If you need more details or have any other ideas or questions, PM me.