@Kasaung Anderson - its really depends on the area you live in. some areas don't support a large house and some does and do not support a smaller one (a 2500sf in the Hamptons wont fly...).

The tenant suffers from a number of health issues and the mold is literally making it difficult for her to take care of herself and her daughter.A simple letter could do the trick.

every state is different but it wont preclude you from renting it.. 

If I go apply for my 4th sfh rental property loan will the bank still count the mortgage payments of the 3 sfh rental prperties as part of my debt in the debt/income ratio or the lender wont count as debt because they are cash flowing?

You would be surprised, some people can't/wont invest in stock market so they want a lower annual interest rate. 

Real estate suffered during the Great Depression (which was deflationary), but soared during the Stagflation (which was inflationary).

are they suffering from allergies or is there a bad smell to the place? 

But who knows, you need to look into it because times have changed and they way things were conducted back then dont mean that a sale of the property wont trigger a tax assessment on the land and then when they come out and notice the park makeup and look at their records you could end up with a big headache. 

Personally, I wouldn't list an unfinished product, because the general public wont see past that in most cases

Who would you evict...the unsigned tenant (where you have no lease- and is a "tenant in sufferance"- or the paying tenant that isn't smoking?