This does add a margin of safety for them.Those wishing to be passive investors take on a huge responsibility during their due diligence prior to investing.  

Make your number one goal being to get the property prior to trustee sale by getting in contact with the owner directly.

I heard of the MLS showing accurate Comparable House Sales and therefore ARV but what else does it show with 100% or Close Accuracy and is there anything beyond the MLS they have access to?

Have the current owner get them out prior to closing .

Hi- I purchased a house at a trustee sale in September in California.  Property tax is current through June.  I assume the bank needs to pay the amount accrued up until the trustee deed being filed.  Is that right?   ...

I trick I use is to find a comparable property I like and then look up the contractor associated with the building permits in the county or city's permitting system.

Can you actually use expected rental income to qualify if you do not have prior years of landlording experience via tax returns?

If you decide to do it, it would be wise to obtain a valuation by a third party or if that proves to costly develop your own comparables to justify your allocation.

Then you'll more accurately be able to compare this investment to others in the area.  

After research and two visits to house (in Sayville, NY) there is interesting situation developing: this property is in very good condition, and need only some paint and few gallons of clorox, utilities are off, comparable houses in area were sold for #380-420k.