I've created a root mysql user, with a different password than the system root user. I use this password to administrate mysql. And I have created a username and password for each database, just to be sure.
Now, that is ok. But I just wondered, what should the rights to /var/lib/mysql be? I've it currently set to Owner: mysql, Group: mysql, and mod 755. Does it matter for the security what this is set to? I'm the only one who's got shell access.
Should be OK. I always set the owner and user to mysql. The permissions are OK as well.