“Can I be held accountable for my future husband’s unpaid lawsuit after we are married?”
Not likely. His wrongs that made him liable sound like they happened outside of the marriage, so this would be his separate debt. A judgment creditor may be able to attach a joint account, and that will make you feel like you are paying part of it. Some collections agent may sieze all or a part of your tax return, and that may feel like you are being held liable. Someone might put a lien against some jointly held property (like a house) and you may not be able to sell it without clearing the lien to the extent of his ownership interest. So although it is not your debt, wherever you and he mix your resources, you may be dealing with it.