Yes it will show up on their credit, but if you're doing well, it'll only increase their credit worthiness later.

Address affordability and credit worthiness by working with a professional who underdstands the laws.

@Joe SplitrockYou will still have to personally guarantee the loan while buying through an LLC, unless it's longstanding and credit worthy on its own, but the risk of operating sole proprietor is beyond any risk I'm willing to take.

During times when banks are risk-averse and reluctant to lend money to any but the most creditworthy borrowers, seller financing can make it possible for many more people to buy homes.

Credit is a racket to some people, but it's a very necessary evil for credits to have somewhat of a baseline model to credit worthiness.

They were almost assuredly saying that based on all the numbers and your creditworthiness, the rent would have to be $1700 for them to approve you for the loan. 

It is recommended to monitor your credit score regularly and take steps to maintain good credit habits to help improve your creditworthiness over time.

The operations like property management need to be in an LLC to protect the property assets and personal assets from the rental or what ever business operations are being performed that create value for the business - but that LLC is not a series and does not own land trusts.As an LLC builds credit worthiness and financial resources, it gains the opportunity for anonymity to use nominee trustees on titles, so the personal buy is not required but the land trust is used to help with anonymityThat said, I really liked @Peter M. advice to use a real lawyer and agree he is an informed investor. 

This should also ensure youre getting about 8% return on your money.3- Business Friendly and Credit worthy State.

You (or the originator) will also need to follow all the Dodd-Frank rules for determining the buyers credit worthiness, etc.FYI:  The Poverty Law group in Michigan is pressuring law makers to enact new laws to seriously impede seller financing with land contracts, lease to own or leases with options to buy.