I try to avoid a double close at all costs (no pun intended). 

Something's not adding up (pun only "sort of" intended).I'd think you'd be able to beat that handily with a mortgage secured by the property, no matter how terrible your credit is...

If you have those types of opportunities easily within reach were you can buy land for dirt cheap ( no pun intended) then sell it on long term contract with your DP usually covering your acquisition costs..

(pun intended!) 

It's ben our experience that the revenue from on-site coin-op laundry is pretty close to a wash (pun intended) when you consider the cost of the machines, the water consumption and the electricity/gas required to run them.In your list of expenses, I do not see groundskeeping (lawn mowing, snow removal, leave raking, etc), nor garbage collection.   

Pun intended.

I realize this is not going to be a popular perspective in a forum full of people trying to make their pockets bigger (pun intended) but I'd consider how many successful people you know who are miserable.

However, I am nervous of the risk of the area flooding again and my investment going under water (pun intended).  

^ nailed it...no pun intended

I am thinking it would tough sledding in the winter....pun intended.