In any case I know that this a valuable learning experience, and I will be writing up and delivering a contract regardless.

Is there is anything I can put on the address block which will make USPS deliver even if house is vacant?

If at any time you don't post the eviction letters, or deliver them correctly, or file things properly, you would have to start the process all over again.  

I have ZERO knowledge about the process of ordering, delivering one of these cabins, what's included and then I have to hire someone to assemble it.

Such as going to property to me tradesman, or last month charged that to deliver paint to a unit so the tenant can paint.

If she doesn't pay, wait until the 3rd or 5th or 7th day (whatever is the law in GA) and deliver a pay or quit notice. 

I would have her sign the lease dated for that day but effective 7/1/15.Be sure to put something in the lease that says it is void (or the dates need to change) if you are unable to deliver the unit to them on time, due to no fault of your own.

Conventionally a 5% loan needs a substantial discount to deliver back that yield.  

We decided to go ahead and close, but only after the trustee signed an escrow amendment stating that no funds would be released until the house has been delivered vacant.

Definitely pay attention to other intangibles, appearance, how punctual they are, do they say they'll get the application back to you tomorrow and don't call/text/email and deliver it 5 days later (adherence to commitment) etc.Des.