"Am I going to have to be the one that checks the buyer/borrower's creditworthiness OR can I have some 3rd party do this so it is more legitimate and I'm not violating privacy laws or executing lending actions without a license?"

The opposite is sort of true prior to some underwriting guidelines where you could have a 450 score and get a loan.So does FICO need to change, nope, more consumers use it now more than ever to gauge their credit worthiness.

Yes, the buyer would still have to qualify for the mortgage in terms of creditworthiness, but he wouldn't have to come up with a down payment if he was just assuming the mortgage.I think the main thing is going to be convincing the seller to refinance with cash-out on their home, unless they're motivated and willing to work with you. 

Regarding credit worthiness:  With your business being less than 3 years old, your personal credit will be evaluated.

Your score tells people how credit worthy you are and how likely you are going to pay back the loan.

Rent payments with the bureaus that accept them are treated separately from all other credit accounts and don't affect their fico score or general creditworthiness.  

If you can't get creditworthy rental tenants, the possible cash flow doesn't matter. 

The loan is based on the value of the asset, not the credit worthiness of the individual. 

@Derek Dombeck & @Wayne Brooks   Just for laughs, here is a model form of Wholesale Contract:WHOLESALE CONTRACTThis contract is made between __________ (“Buyer”) and __________ (“Seller”).Buyer agrees to sell the Property described below to Seller for $__________.The Property is described as follows:________Buyer shall not be required to deposit any earnest money into escrow.The closing, if any, shall be in 90 days at such time and place as Buyer shall choose, in his sole discretion.SELLER UNDERSTANDS THAT BUYER DOES NOT HAVE THE FINANCIAL ABILITY TO BUY THE PROPERTY FOR CASH OR THE CREDIT WORTHINESS TO SECURE A LOAN TO BUY THE PROPERTY. 

Don't carry revolving debt or balances of more than 30% of your total credit worthiness, pay your cards on time, don't close old accounts and be sure to resolve an outstanding balance discrepancies that any of the 3 major agencies may be holding against you.I always advise on checking your free credit report once a year from each of the 3 reporting agencies to be sure there is no false information or accounts that you don't recognize.