Sorry to bump thread, but quick question on similar issue myself.
Installed WordPress and LEMP using the brilliant EasyEngine setup, however facing familiar problems when trying to upload/migrate existing files/folders to WordPress (wp-content etc).
I have created a root-privileged user for myself using a separate SSH port etc, however I want to know one thing.
I tried much of the tips advised such as "sudo chgrp www-data wp-content/uploads" to no avail.
I then added this line: sudo chown -R myusername:www-data /var/www/*
It seems to work fine - I can upload plugins etc, however I want to know if it is safe. Is there any downfalls to using that approach, or should I avoid it?
I found it on a Google search where people using Apache used it, however, does it make a difference considering I'm using Nginx?
Thanks a lot, and sorry again for rising a settled thread!