Is there a way an elderly couple can sell their property, but live there until they pass?

Given their age and the property's location, I feel relatively certain that you could find an investor who would buy the property at a discount...

Do I automatically become responsible for my future husband's debts?

If you marry this guy, bet a prenuptial agreement!

You are on thin ice, but I basically agree with Attorney Paine. I don't think that the DRE would be concerned with a one off deal but they might..

What about our /his life insurance if he was to die and they found alcohol in his system

That should not matter, especially after paying premiums for over 20 years.

Can you maintain a mortgage in someone else's name after inheriting a property?

You should re-fi the house. I'm sure that your uncle's lender had a "due on sale" clause in the loan which means that the loan should have been...

What steps can my best friend take to protect her from future bills etc caused by her husband?

What immediately comes to mind is that she can divorce him, or she can make him sign a marital property agreement.

They can, because this is a community property state, but under the scenario described, they usually don't. Nonetheless, one spouse filing...

Can I sell my house to my brother.

Make sure the house appraises for no more than $750,000. Otherwise you have made a fraudulent transfer that the Trustee will unwind.

How do we transfer my deceased my-in-law's property into my name? Do we still need to go through probate? Who do we call?

If the property is appraised for over $150,000 you will need to do a full probate. If it is worth less than $150,000 you can probate by affidavit....

if the spouse is the CoTrustee and Agent, how can you keep Principal's property separate and avoid conflict.

You need to provide more context to get a meaningful answer.