Youd do well to pick a geographical market that you are working (your "farm") and systematically driving the communities and get to know every street by driving in your car first, noting where the problem activities are, etc.Then define what a "deal" would need to be for another buyer or for you to use your money and keep.

They have made me write a lot of explanation letters.

@Charity Woods Thank you for that explanation...playing with that idea myself.

Even if it did get bid up a few thousand dollars, I think it would still be profitable and worth it (depends on who you ask though).I'm geographically familiar with those areas I lived in South Euclid and Lyndhurst each for a year.

http://www.tomferry.com/blog/dominating-a-geographic-farm/

A more effective approach is to target a particular limited geographic area, preferably an area in an upward transition.

Even the manufacturer's websites do not provide a clear explanation or distinction.Do you have any literature from your contact that could be used to present it to the departments?

I have never been there so I do not have any geographic things you should consider but I do have a few things to say.  

The good thing about FHA products is that a good letter of explanation can help him/her get the loan through.

For a definition of this FDAP vs ECI stuff, see explanations in Nolo Guide to Landlord.