spent the day solving my own problems:
PCLZIP still needs some work, but it isn’t always what people seem. Apparently there is an issue with a site-key from WPML that won’t update. I’ll post back here when that gets fixed, but at least we know the source of the issue, more or less.
HTTP error was a result of Nginx having no maximum file size for upload defined. I added client_max_body_size 15m; to the nginx.conf file and boom. All fixed!
