Change root user/group of the synced files (linux)

On my dev computer, I have decided to create the folder called “www” in the root of my synced files.
My idea was to copy all my php files served by apache in it.
[As you can understand, my goal was to have my php dev tree directly synced and shared by Insync]

Unfortunately this is not working as ALL synced files have the following ownership/permission
-rwxrwxrwx 1 root root

and apache needs to have ALL the served file in the www-data group.

Thus my question is: how to force Insync to use at least another group? And maybe another user…
My second question : is it possible to change the permissions of some files (ie: set read only)?

Please let me know if my question is understandable, as English is not my native language…