I'm a buyer -- 1st & 2nd lender approved short sale

[Tommy Daniels]

I am a new investor looking to purchase my 1st rental property.  It is a 12yr old townhome in good condition that will require minimal repair to be rentable.  The 1st and 2nd lienholders approved my first offer of  $80,000 cash.   I recieved documentation addressed to the seller that is probably not intended for me, but the lender approved a discounted payoff for the seller at $66,400.  

A friend ran the numbers through the biggerpockets BRRRR Analysis calculator and my Income-Expense ratio (2% rule) is 1.12. I plan to rent for a conservative $950/month. I will be cash flow positive at $319/month. Cash on cash ROI is 4.5%. SO, in order to get more equity and improve my numbers, I'm thinking that during the due diligence period I will ask for a lower price around $73,000. I'm assuming/hoping the lenders will accept or counter my offer and not have to go back thru the approval process.

Any advice about my thought to lower my purchase price?  Should I request that before putting down earnest money and paying for inspections?

Should I mention this to the seller's agent who is acting as buyer/seller's agent, since I didn't use an agent?