Note, next time you will be banned for such inappropriate expressions.f****ng nasty bug
If nginx is a reverse proxy for another server, I think it won't deliver static filesYou'll still have your Nginx as a reverse proxy, and it will still deliver static files, hence speed up your website. It will however simply read the files from disk when they are requested and not store them in its cache.
"deliver static files" means it delivers them on its own, reading from the vhost's path in the filesystem, not getting them by asking upstream. If the website really is on another server, that won't work for reasons that should be obvious.But it seems it does - at least with my config... since i gave that ~18GB file download link (due to a bug report) to a company for investigation, Plesk started