It just needs to be rent ready as the appraiser will do a rent survey and that rent amount that the appraiser comes up will be used to structure the loan- more on that below. 

The land was surveyed incorrectly.

The appraiser will provide a rent survey and a rental amount that will be used to structure the loan- more on that below. 

If this isn't clear enough, one could survey the other bank loan officers and see if the other doctor notes included this term around the year the loan was written, if this is one of only a few outliers which they threw the term in for, then any jury would likely conclude it was unnecessary and the power of attorney would make that void... but they as you say if the bank makes all the rules for their conventional since it's not "conforming..." then they could call the loan due and as you said the refi would be needed regardless. 

You're also going to need survey and engineering work to get the permits done for putting in the utilities to the buildings, flatwork and other improvement requirements around the buildings.

But like others said, I would secure the home asap, survey the home and put it back on the market or make ready to sell like you may consider.

I did a survey last year and spoke to 8-10 lenders and they all said they wouldn't add extra value to the property based on it being a working STR.You need to check comps of other mobiles in the area of similar quality and price it accordingly.

I did receive an email 14OCT from Frederic Robinson about filling up a survey. 

Normally when people ask about something like this, they are looking for a quick way to survey markets, but that's not a great idea if you guys are brand new.

I just think it's wise to survey the opportunities in your area for both and find the best deal vs. upkeep meaning don't try to also do value add on a large scale.