If it's already built, you'd basically get a HELOC or a home equity loan. If you owe $80K, my guess is that you'd have a much better rate with either of those options then what a credit card company provides, so I'd definitely look into to! Plus, you'd get the tax advantages on the interest (at least for now!)

Go to bankrate.com and you can see where rates are and there are calculators to figure out the differences in payments/rates, etc.

Depends on your credit card interest rate and how likely it is that you lose your income, if this is necessary to pay back loans.

While home loans are usually lower interest and tax deductible, you put your home up as collateral vs. unsecured credit card debt. So if your income goes bust it's easier to discharge the credit card debt than potentially losing your home.