How do you handle the calls and prescreenings on the phone and what do you do to blow off undesirable sounding tenets right from the start ?

The only small piece to add in addition to the above (scoping out contractors at Home Depot and Lowes at 7AM, and your current contractor referrals)... on big jobs you can also consider using a cheaper labor service (~$12/hr) for peripheral tasks, depending on the rehab.

Thus his undesire to help.Anyway, it's my understanding that you buy the property from the owner, not the trustee (given the trustee approves the terms and the price).If you wait for the end of feasibility period, this is likely to play against you for the seller will be able to get off the hook (contract) legally.

In 2nd position, with no equity, with an undesirable property, it could be a lost cause to milk it much further to recoup losses. 

Even then it is unlikely (and even undesireable) that you will find a 3rd party team member to do the two most important steps: 1) "selling" the group on the plan (from conceptual plan to "closing" the deals with each individual purchaser) and 2) finding financing.

Or it's an undesirable neighborhood.

We did not need to evict any tenants, but the undesirable tenants left on their own once they learned our management style wasn't to their liking.

Is there any reason that you exclude properties in the undesirable neighborhood?

In the renter's policy, the property owner (and we, the management company) must be indemnified against any/all aggressive behavior by the dog.There is a list promulgated by the Insurance Institute of, shall we say "un-desirable" or dangerous breeds of dog. 

They're generally not undesirable.