1) Your spouse's credit will be affected if you share joint accounts, or if your spouse is an authorized user on an account that you fall behind on in payments.
2) Regarding spousal debt, see Is My Spouse Liable for My Credit Card Debt?.
3) I am reluctant to answer your furniture question because it is highly dependent on Florida's replevin laws, of which I am not well-versed. I recommend you take this question to a Florida attorney experienced in consumer rights law.
4) Cash advance from a payday loan storefront or a cash advance from a credit card are both unsecured debt, and receive equal treatment under the law, generally speaking. If you are referring to a so-called payday loan, see Payday Loans in Florida to learn more about the rights of Florida consumers. However, if you are referring to a Home Equity Line of Credit (HELOC) or a home equity loan, those are secured by the property.
5) If the HELOC/home equity loan/second mortgage are paid in full, there will be no negative impact on either borrower's credit score. However, read Information on consequences of default on a second mortgage if you decide to take that route.
I hope this information helps you Find. Learn & Save.