I'd choose number 3.
3. Move to a new house and cut off the relationship with him.
It's really dangerous to live with a gambling addict, if he's taking out a loan and can't repay it, the debt collectors aren't only force him to pay off the loan, but the family also get charged too. Imagine you've work so hard, learning everyday, and have invest a lot, but there's a day the debt collector force you to pay off the loan even though you did nothing.
What if it was your own house, would you buy a new house only to leave your house and be left with a gambler who could sell your house because you are still related, unless you directly take action as discussed in the thread, yes even if there is It's true that we can get away from him by avoiding him, but he is part of the family, it's best if we can help him get out of his gambling addiction. I'm sure that with gentle methods, gambling addicts can be cured even though it takes a lot of time.
There are so many gambling addicts who can be cured in the right and appropriate way, therefore it is not the right way for us to move house if in the end we can use the right way to cure our family who are addicted to gambling, the point is don't be too uncaring about our family, even though he is a gambler or has made a mistake, he is still part of our family, we should carry out our duty to make him better and aware of his mistakes, that gambling will not be fun in the end, I am sure of That kind of gentle way of advising had helped him become better.