How long can a person live after being diagnosed with cirrhosis of the liver?

A long time. Cirrhosis means scarring of the liver. Patients can live over ten years with cirrhosis as long as they do not have other complications like liver cancer, GI bleeding or encephalopathy or peritonitis. Once one has a complication from cirrhosis, they are defined as decompensated cirrhosis and often have an average life-expectancy of 2 years or less.
Depends. Depends on the cause and if there is a continued insult to the liver (etoh, etc). Noone can predict with certainty.