When I look the property up on the county website it is zoned single family.It's an older home so I assume it has been divided and added to over the years, probably prior to rigorous permitting and zoning laws.I would like to ensure that everything is legal prior to possessing the property, and imagine I would need it to be so to use the rental income towards the loan.So I guess the questions are:Is it silly to think this could be re-zoned?

Unless the OP wants to be a property manager for the entire time of property possession, he should factor in 8-10% for management and a 5-10% vacancy rate.

No money changes hands until possession is delivered to you.

Just a note that in light of this newest legislation, we've also added the screening criteria "applicant must be willing to take possession within 2 weeks of approval" because the SMC is so poorly written that the first applicant could want possession 3 months from now, and what's stopping them.  

If there were no other heirs, you can quiet title three years after the tax deed if you've maintained continuous possession during that time.

You're playing with Fire and could potentially get burned badly.At this point the bank is almost irrelevant because they don't own the property,the seller does.You have to negotiate with the seller and make a written offer to be taken to the bank for approval.Not going to be easy with a short sale situation and the bank is already upset with the seller and now preparing to foreclose soon.The tenants are going to be the hardest part in this mess because they have just restored their tenants rights with the accepted rent whether it was the entire amount or not.I doubt the bank will stop the auction unless you offer much more cash than you should and no contingencies sight unseen.Expect the inside to be trashed and need a full gut job remodel and make your offer accordingly.You'll have to formally evict the tenants after taking possession

That's the shortest term you'll likely find, but that may lead to some hang time between notice and actual return of possession, which should be counterbalanced by the rent you'd receive. 

With the UD action, the ploy is to gain possession, not rents as with possession I can cleanup and get it rerented ASAP.To get Past Due rents and fees, file in Small Claims- - again, don't expect to collect as they will have nothing to attach - - so write it off as Bad Debt.

The current sellers, in conjunction with the previous owner, received an offer by a prospective buyer to buy the property, included along with it some additional land abutting it that the previous owner still possesses and wants to sell.  

In Milwaukee, WI the municipality forecloses for delinquent taxes and then takes possession of the property.