If they have no proof that they notified you of the problems, then how do they justify withholding rent? 

Just curious, how did you get a 9-unit under contract without a pre-approval or proof of funds?

Your lender may be looking at cash reserves or proof of funds.

It is really the Trustee who orders the sale based on notice and proof from the Mortgagee of default.

Also at closing: You should provide proof that the lender is named as such on a valid hazard insurance policy effective at least on the day of closing.Regarding the closing to sell or refi, yes, your lender will just need to provide a payoff letter with wiring instructions to the closing agent.

I'll ask for the proof of their enrollment to the colleges and I'll talk to their previous landlords.

You would need to file a proof of claim for the monies owed and hope you secured it by a deed of trust.

@Larry Nielsen We’ve found a great way to raise rent is:Determine market rentShare the proof with the tenant (they can see it on Zillow anyways)Tell the tenant, given your rent is $x and market rent is $y, what do you think if a fair increase?

I would include in your future offers that you want sellers to show proof of lead cert, if not have them pay for it as a part of the sale if it is not present. 

As an investor-focused agent in the Cleveland market I always have my clients write the following contingencies in when buying a house that's tenant occupied:1) Offer contingent on home inspection- usually a 7-10 day contingency period, this contingency allows you to either A) move forward with the deal B) renegotiate the price if issues are found, or C) walk away from the deal2) Offer contingent on appraisal if you're going financing3) Seller to provide copy of current lease agreement4) Seller to provide a rent roll/tenant ledger with proof of payments received5) Seller to provide copies of 3 previous months of any utilities paid by the landlord6) Seller and tenants to fill out Estoppel Certificate.