asylum Seeker with Family

Hi All,
I have got a set of questions here. I have got one friend, who is living in UK for last almost 10 Years. He is over stayer for over 7 years with his family. He is thinking to apply for Asylum alone. He has got substaintal evidence that his life is in danger in his country of original. Now the question is Shall He apply for asylum alone, Is it a right thing to do? second Obviously HO knows that he is in UK with his family, What are the chances of success applying alone? Third for an argument sake if he has been granted Asylum, What would be status of family? Would he be able to get his family beings dependent on him after grant of Asylum? Or his family (who does not have any substaintal danger) in the country of origin will have to leave the country and apply outside UK? If this is so What would be the minimum period, a fimily will have to be outside UK, before they are eligble to apply?

I know the situation is quite tricky and awckward, but all the senior members are very experienced and can easly answer to all these question.

Thank you all for taking time to read the post and I would really appreciate if you could reply as per your knowledge.

KInd Regards