Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

Document the transaction clearly and consult a tax advisor to ensure the structure is compliant and minimizes tax liabilities.4.

Separating Y and taxing it as an S Corp could be beneficial if you're looking to take advantage of those tax savings, but only if Y's profits justify the additional administrative burden.Rental Agreement for Home Office:Yes, you can lease your home office space to your LLCs, but it’s crucial to keep everything documented and ensure the rent charged is fair market value.

When there is a recently acquired long-term rental, lenders can simply throw in the lease agreement and use 75% of the rental income from that, but on a short-term rental, there is no lease agreement, so the only way to document what the actual cash flow is, is by using Schedule E of your most recent tax return filing. 

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

In my experience these are the levels of how financial fraud is doneLevel 1 - The “sponsor” is a fraudster from the beginning and the entire investment is a designed fraud designed to steal the investor's money Level 2 - The sponsor initially intends to operate legally and honestly but the temptation of easy access to money, usually fueled by addictions to drugs, sex, partying, etc. leads to the bad decision to line the sponsors own pocketsLevel 3 - The sponsor intends to operate legally but a crisis in their life resulting in a need for money leads the sponsor to “borrow” from investor’s funds with the full intention of paying it back ( which they are unable to do).Level 4 - The sponsor intends to operate legally but the assets under their management incur substantial loses; the sponsor attempts to cover up these loses by “temporarily” borrowing from one investor to pay another or submitting false results.

The potential issue is documenting your intent. 

They would need to sign a document for the termination of the town home lease and starting up of the new lease for the other property. 

A title company can help you draft any necessary documents.