Well you nee more backup besides on recovery program of Recuva caused chances are, files might be damage even retrieve it, so store them in USB/External HDD alongside through cloud and conducting system image of your system to restore any changes in case of emergency.
Also CCleaner is fine and you may add defragmentation software like Auslogics Disk Defrag or built in from Windows.
Optional: Since multi-shared you may activate Guest account/Limited user account to limit the privileges of executing/using programs without your permission.