Your post is very unclear and is, I think, asking the wrong questions about the wrong issues.
You are married to a person who is feckless with money. He risks his family's security by borrowing money he does not intend to pay. He puts his own assets at risk. He has put the family home at risk.
I gather from your posts that the family home is not held by you and your husband in joint names. Perhaps it is - but it's not clear and it's not likely as you say the bank have the Title Deeds. If both names are on the Deeds, then both parties would have to agree. So is it true to say that the family home is held in your husband's sole name?
Certainly, the bank may have difficulties in enforcing any security they may have over the family home. However, the idea of somehow seeking to hold the Bank negligent, for lending your husband money, because you told them what he is like, is almost childlike. The real issue is your husband's attitude to money and what his behaviour does to his family and to you.
Talk to a solicitor about how to safeguard your own security. If you intend to stay with this person ( and you talk about him at retirement age), then you need a massive re-think on his and your own approach to his money difficulties.
mf