I've seen that ISPConfig places a /stats/ directory under web. Is possible to change this path? I don't like to customize files and folder inside a directory used by customers. What will happens if a customers already has a /stats/ folder inside it's website?
The folder is created before the customer is even able to access its website the first time, so this folder always exist when the customer gets access to his site. The stats folder is a reserved folder name in ispconfig and may not be used for custom pages. Thats the case for all ispconfig versions since 2.0.
As I can see, /stats/ folder is referenced only in apache module and cron script. It should be pretty easy to move this folder outside webroot, if referenced only in these two files.