Glad to hear. You might want to check your nginx is up to date as well. Nginx will still work with an older version, but it will act funny...
Use this to get up to date:nginx: Linux packages
I am using redis and the data is stored in dump.rdb. Everytime when I want to backup this file, I need to ssh to the server. Is it possible to achieve this in ACP? I think it is a good feature. Or, is it possible to send this file every other week to some Email address?
With cron you can automate pretty much anything you can write a script for. That includes sending files around.