If we did not reaffirm on mortgage after filing Chapter 7, can we walk away from the mortgage?

The Chapter 7 gets rid of the debt you owe on the mortgage. So you can just walk away and let the bank foreclose. However, the bank doesn't have to foreclose. If it doesn't, you will be on the hook for taxes and any other fees associated with home ownership (like HOA dues etc.). Your better option is to arrange a short sale with the bank.

Yes. All discharged in your Chapter 7.

You have no obligation to the lender on the mortgage because it was discharged in bankruptcy. the forced insurance is part of the mortgage, so you won't be on the hook for lender placed insurance. But you're still listed as the owner of the house - so you're liable for the taxes, the obligation to keep up the maintenance and you're liable if, for example, a kid wanders into your house and is injured. In some states, there can be criminal liability on a vacant house as a nuisance. The best way out of this is to arrange a short sale with the lender, then your name gets off the house.

If you did not reaffirm the mortgage, then your personal liability has been discharged. In other words, if and when the mortgage company forecloses, they cannot pursue you personally on the mortgage debt. Property taxes do not carry a personal liability. They are only secured by the property. So, if you fail to pay the taxes, the mortgage company will be responsible for them and will have to pay them if they do not want to lose the property through a tax foreclosure. If you stop paying the homeowners insurance, the mortgage company will be notified and will most likely obtain an insurance policy (FYI their policy will not protect your personal items inside the home). Until the property is legally transferred through a foreclosure or other means, you should make sure the property is adequately insured. If you do not, you may be exposing yourself to potential liabilities (i.e. person is injured on property and sues you). Typically, I advise clients that are in your position that they can walk away with no issue as long as the property has the appropriate insurance coverage and the property is maintained in a way that avoids violations of city codes/ordinances (avoid tickets). Insurance and maintenance of the property should continue until a legal transfer of ownership occurs.

Yes you can walk away without any liability. If the bank puts forced place insurance, you do not have to pay it - that obligation ended with the loan. However, as long as you are the record owner you can be responsible for the property taxes.