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

What is the typical minimum investment requirement?

Here is a list of minimum Requirements: 1.

Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.

Most lenders require the delinquent balance to be paid before approving a VA loan assumption.

For a 3-4 family home, it's more complicated—you're looking at commercial lending, which requires a large upfront investment, high holding costs, and greater risks.

If you eventually convert the property to your primary residence and later sell it, the taxes would be prorated based on the ratio of time the property was investment property.These items should be addressed and discussed with your tax and legal counsel to ensure that the exchange is the best course of action given the restrictions and requirements. 

Also do research on what's required to properly manage a LLC so the veil cannot be pierced. 

First off, the cash-out refinance requirements have gotten tighter w/ the "seasoning" period.

This may require a co-signer, such as yourself.