Hello,
Sherri offered you excellent advice, but I just wanted to contribute some words of support as well, in case it helps. It is a very difficult situation you've been put in, and although it's difficult it's the right thing to do talk to your husband and together consider all of your options and the potential consequences so that you can make an informed decision.
From what I know of liver donation, it is more "dangerous" than living kidney donations and the outcomes are not as consistently positive. When being faced with death, I can completely understand how it could be difficult for your husband's family to recognize the potential risks of complications and even death of the living donor. You're right, they may not be completely informed right now, or acknowledge the honest facts.
If your husband is truly considering living donation, he (and you) can certainly meet with the living donor advocate at the Transplant Center. You should definitely ask about it, because every Transplant Center has a living donor advocate, social worker, and transplant coordinators who would be extremely informative. Plus, it's their responsibility ethically to walk a potential donor through the entire process, outline the risks, and answer all of your questions. They might even be able to help facilitate a discussion between your husband and his father, or give you some feedback on how to approach a discussion. The social worker and/or living donor advocate would be skilled in counseling and advocacy to help you through things.
As Sherri also mentioned, if your husband proceeds to go through the tests to determine he is a match, he will ALWAYS have the opportunity to step out of the donation. From my experience as a kidney donor, I know that the Transplant Team is quite thorough in determining whether a living donor is suitable, so there's still the possibility they may decide your husband would not be a good match, either because of compatibility, or because of other potential risks to your husband's health. Typically if a potential donor decides to "opt out" for any reason, the Transplant Team will cite a "medical reason" that prevents the donation. This might give you and your husband difficulty because it would be dishonest to your family...but in the end I feel it's a significant long-term decision that all parties should be able to live with, whatever the consequences.
Take care, and I wish you all luck.
Dora