Given that there have already been a few surprises with this property and I'm not sure how confident I can be at this point that the deal will progress to closing, what's the best way to minimize both mine and the Seller's out of pocket exposure in the event the deal falls through quickly?

If I can make a 3/1 I am confident I can get 1100 a month in this area.  

I'm a Realtor and also investor/flipper/landlord and I feel confident I could made a qualified purchasing decision on a property if I had someone via smartphone allow me to walk through, see details, drive through the neighborhood and provide me with any additional data needed.

I have been actively looking for a multifamily in the Manchester Nh area and feel pretty confident (I think!)

Is it ok to sign this confidentiality agreement with multifamily brokerage firm?

Though by that time, with appreciation and some repairs I'm confident I can at least break even if not a small profit.

Most end cash buyers are fine with wholesalers making money but if there is a huge spread I keep it confidential. 

And what data sources do you pull in for determination (if it's not confidential ;) ).

This one, we just closed on 2 months ago, so I'm confident I can work that cash flow up a bit higher.

I’ve been back and forth since1998 and feel confident I know the area, but there are more knowledgeable folks than me.