When purchased, technically, it was a 7.5% cap, now at about 9 cap, and in Sep, 9.74 cap.  

On top of that, I expect to defer quite a bit of taxes from the capital gain of my flip.There's one big technicalities I'm not quite sure about ...Per my understanding, 1031 only works for exchanging investment properties and cannot be used for primary residence. 

From what I understand it is bad practice to rent back to the seller...he is having financial problems affording the house so technically he wouldn't qualify to rent it if he went through a normal tenant screening so I would say it is a better bet to find new tenants and tell the seller he has to move at COE...think about the emotional attachment a seller would have to house he used to own but now has to rent...

You can take the pure loss to compare it to renting because with renting you're losing everything as well if you dont want to get to technical (since all tax payers have a 6300 dollar deduction in 2016 for single filers whether you buy or rent you get this and its an either or deductions if your itemized deductions are higher you get your itemized if they are lower than this you get the flat 6300 standard deduction "either or.").This standard deduction vs itemized deduction issue complicates the rent vs buy but if you want to look at it simply you can use my explanation of the net cost of buying vs renting as the main consideration.Does that make sense?

So its technically not a duplex, but it works just the same. 

Technically, you've done everything correct.

When using a realtor to find a property that you end up wholesaling, what is the general protocol for paying them if you assign the contract and technically never close?

The rest of Fairfield East of I-80 is pretty bad, and I'd steer clear of that area.Next is Cordelia (though technically a Fairfield address), North of I-80, in a community called Green Valley is really nice, again more expensive.

Should I consider paying the contractor for their down time today (technically I'm at fault for them not working today given I committed to the home being available today)?

from what I have experienced, like anything you get what you pay for, there are 3 factors with contractors, Fast, Reliable, and cheap,  pick 2,  you will go through these guys like water, then find one that seems good, till they flake,  my experience has been, they always want to get paid before the work is done, "to pay their guys" or something, but they rob peter to pay paul, and are always behind a job or 2, the economics generally doesn't work to hire the expensive reliable contractors, so you end up managing the projects,  I have a Painter/drywall guy, a Handyman, and Carpet guy, i do most of the technical stuff because I dont trust anyone to do it right (my personal issue) you can make the numbers work on higher end, properties, or mid/lower if you squeeze your margins.