cli lightweight. then it really not easy and direct way to learn it. perhaps very few locallizaztion tutorials to learn linux's specific parts,so I directly search Google and english Tutorials.

And it maybemisconfiguration somteimes when want to improve so called "security",fail2ban,ufw together with tc.

so mostly left default!As other said,if you don't fully understand whatthis part means,you'd better not change with parameters,linux do not need Virus-killing tools,system default ismuch safer than youself.(see on stackoverflow).