Although she hid this information from us and no real way to know this guy existed. 

It's important to be aware of Such requirements if they exist in WI.

If I were to "purchase" a property "subject to" the existing mortgage, could a quit claim deed be used since the seller is in a must sell position, and if so how would you profit from using a quit claim versus signing the contract for the seller to keep the financing in their name fo 3 years?

A door with a window would also be more inviting, or paint the existing door a fun color.

@Steve Might  if the existing wiring was all done correctly and working correctly then adding this compressor would not have caused any problems. 

Its easy to find another proposed tenant to move in so you have no potential issues with the bank or the existing tenant/owner.

When dealing with title, buyer agrees to pay seller 5k, buyer agrees to purchase property subject 2 the existing loan not to exceed 100k.

@Dustin Morgan , I look at this similarly to an investor buying a property "subject to" existing financing, I.e, assuming debt.

Two years ago we actually put 80k cash into an existing property of ours to bring the Loan to Value Ratio to where we could refinance a 6.5% interest loan to a 3.75% interest loan.

@Steve Babiak @Hattie Dizmond In your equations you guys did not account for the existing loan mortgage on the property.