After your debt service of $800 a month, you will have $40 a month leftover.

They are about to formalize the legalization of airbnb in one's main residence SFR, while banning it in R2 or above zones.

Ed, there is not enough information to answer your questions.did you foreclose the right of redemptionhas the judge sign off on your tax sale certificateis the property occupied or vacantdo you have to file an eviction of the existing owner or tenantdo you have enough money to foreclosedo you intend to get a mortgage on itI have done many tax sales deals - my objectives could be ..... 1. sell it now after legal ownership is acquired2. clean it up and sell it for a profit3. keep it to rent4. offer it at public auction - let others bid against others to push the price way up5. sell it back to the owner6. put together a joint venture - raise money to renovate it 

Debt more than you want to pay doesn't necessarily mean more is owed on it than it's worth.  

Are there any legal paperwork steps to take to avoid a bad outcome?

I am a wholesaler in Miami area,   if you are planing to do the same you need to have the right to sale it, I will use a legal approved contract,  you can ask a Realtor to help you with the offer, ask for 0 days for inspection, better with business days,  on that period you will have the time to sale it

Is there any way I can make this work legally.

Facts:$757k purchase price$752k total debt, $260k of which is past-due debt$925k ARV, only needs paint & carpetGross profit, before the costs of financing, is expected to be $90-$100k.  

or is there some legal way to find out why it was abandoned?

I am very lucky because I have zero debt and no bills other than phone and food since I decided to get rid of my car I have no expenses now.