So a deal once found attractive based on which I bid is turning out not to be so attractive.

These books teach you how to handle situations, how to find solutions based on your value system, set clear boundaries with people and overall understanding people's motivations and why they do what they do (which is extremely helpful in any interactions with people).

I did find out however that it could be, based on zoning map, switched to a multifamily from a single family.

Either they can sell the note on the secondary, the price of which is determined by a reasonable yield calculated based on risk and return, or they invested in a security, and are at the mercy of the manager. 

u can not require in most states for tenants to do maintenance only to keep neat and tidyI offer a base rent -0 per cent above market and an early "on or before rent due date received" payment discounted rentNot a late feeIf you do NOT enlist in a mortgage qualification coaching service and leave the tenant to procrastinate on get loan pre qualified, in 30 years of doing lease options I see the tenant not being successful at getting a home loan

I know this is a guide for HUD subsidized housing including (primarily) Section 8 Project-Based Assistance.

Based on experience so far I don't think that would be cost effective. 

Are these numbers drastically different based on location?

Pre-approval for a Mortgage means you are approved for a total amount of added debt based on the monthly payments you will have to make to pay off that debt.  

Still very useful tool and all you have to do is look how high above or below the zestimates comparable homes are listed for to give you a good base to start with.As far as forecasting values, never make a decision on this hearsay.