@Martin NealI'm experiencing something similar but, were locked in for another 9 months.

Lock it up first, and give him a 10 or 15day  inspection contingency, that will give you plenty of time to find an investor and also research on the best possible strategy to profit on this deal. 

I’m trying to see big picture, beyond this first door, so I don’t lock myself out of more purchases while paying this first one down.

Any changes there could significantly impact the outcome.Lastly, 4.25% interest rate isn't out of the question, but again, you want to make sure that is a rate you have locked in with somebody, as a first time investor may be staring down something in the 5%-6% range. 

Another complication is current leases for example if the building is locked into a long term leases at a rate that's lower or higher than market then it could be a discount or a premium to the building valuation.The above would just get you an estimated value of the building.

List Price: $319k Total sqft: 3000Total rent: $2000(4-2), $1400(2-1) may be a little higher depending on conditionPoints by lender:  .75Rate: 3.9% (Not locked in yet)Closing Costs: $4000Rehab: $5000(one unit hasn't been updated and the other has)I am seeing the house tomorrow.

I had a friend tell me that there lender called them today  to lock in rates on a primary because rates are getting ready to sky rocket.  

Is there a gate with a lock or key code? 

I don't know why it was removed (couldn't open the lock box?)

That being said, I was curious as well if an LLC and a lock tight contract is suffice enough to protect myself, and of course my investor.