Well, 命 and 生活 is a bit easier, so let's start with that. 命 is life with the everpresent idea of death attached to it. As in being a matter of life and death, or someone taking someone else's life, or soldiers giving their lives for their country, etc. When talking about your daily life, or how your life changed, or that your life is happy, etc. etc. one should not use 命, but 生活. This term is used to cover things about your daily life, livlihood or daily existence.Could anyone explain the differences between 命 and 生活, 仕事が欲しい and 仕事がしたい please? Thanks.
As for the other set, 仕事が欲しい seems to be a general expression of desire/want for employment. The best translation would be "I want a job". However, 仕事がしたい is to "want to do a job" and is used more when the type of employment is specified. So, if you were to say, in English, I want a computer job, in Japanese the best way would be to say パャRンの仕事がしたい or コンピュターの仕事がしたい i.e. I want to do a job in computers or I want to work in computers.