Most of the ones I bought had existing tenants and almost all were paying below market rents and way below market rents.

I had a cost seg done on one of my homes and trying to get one done on another from this company that rob with bigger pockets had done a set on.Every time I email them it says there email doesn't exist and cannot get a response.

If the agent is their own broker and a sole practitioner then you need someone else to decipher the agency relationships that may or may not exist.

As others stated, if the existing structure is legal but non-confirming that should not be an issue.

But a realtor will not know these underlying lots exist and for sure wholesalers wont have a clue.

How much "fat" do you believe still exists within that? 

It's an 860sf unit, so it would be right around the $2.00/sf mark as a LTR, if not a bit higher.I inherited an existing long-term tenant in the first floor apartment, so that unit isn't in nearly as good shape as the fully renovated upstairs unit. 

this has caused significant delays with a cash out refi on an existing rental.

You also need a detailed explanation of each cost item to solidify a clear scope of work for that specific task.Experienced general contractors provide computerized plans to show the current existing conditions and the proposed final floor plan.

 I'm not opposed to subject to, but my fear is whoever I am taking over the existing mortgage from will not continue making the payments.You make the payments.