If you have 20 homes, even 5 or 10 it is best to get a master policy to cover all of your property VS individual policies. 

Is this an issue given the seller (LLC) and buyer are the same individual? 

“In order to be Fannie Mae warrantable and/or FHA approved, condo complexes must meet certain specifications for the percentage of owner-occupied units, the number of units owned by one individual or company, and the amount of reserves and must be in good condition and free of litigation.”

I am surprised by your comment on Bridge @Nathan Brooks is one of the most respected individuals in the industry.. maybe something fell through the cracks and he will want to know about it.

during refinance of 4th house, i asked banker if i could loan against the equity in house #4 to use as down payment for this house, #5. stopped #4 refinance and refinanced both at the same time. they were both refinancing and closing individually.

The rest focuses on the individual deal and if its numbers work.

What are some ways to secure financing for short -term Airbnb rentals knowing that they are more of a buy and hold.Any advice from individuals who have done this before on the best way to secure financing? 

All depends on the mood of the individual inspector that day. 

Some individuals may not be familiar with the website or prefer to use a different method for various reasons (tech problems, how they set up accounts, income structures ect).

They often outperform individual investors if we exclude owner-occupied financing mechanisms which you wouldn't be able to use at scale with $4M anyways.TLDR:You can invest privately through real estate funds.