I recommend you read this book, download copies of your state statutes to educate yourself, and then start building a "book" of policies, forms, form letters, and other resources just like you would any business.You're only managing one rental, so don't go overboard.

Due to general unresponsiveness of the HOA we did not seek any permissions.However, soon we received a letter from the HOA attorney with request to remove the privacy walls and the foundation support bars with fines for every day not complying.

My lender is asking for a letter describing the reasons for the cash-out refinance and what I plan to do with the money.My plan is to invest in additional investment property and invest in several ETF’s or low-cost mutual funds.

Now if new owner doesn't renew, their head is on chopping block for not continuing to have permit in place but are renting it out. 

Send the owners a letter a couple times a year stating that you are interested in making an offer on their property and asking if they are open to discussing their future disposition goals for the property.  

What you can do is provide a letter of commitment from a hard money lender showing them that you or your buyer has funding available to close.

This property was being marketed as a development deal of an entire city block.

Which surprised me because I went in to the deal with a much much higher pre-approval letter.

My question, any recommendations on what should be in the offer letter?

Since the Municipality has separate Lot and Block Numbers for all three parcels, and taxes them using those Lot and Block Numbers, I don't understand why the County Clerk is unable to find them in the County database.This is an interesting situation and I will keep you updated.