The property is still under construction, but I'll be ready for tours on X/X/XXXX date.

If you sell at a later date all of the tax will come due for all of the chain of 1031s back to the first one. 

If you received your "no" before that date expired you have the right to get your earnest money back.  

She rented the lot only from us, on a m-t-m agreement, and owned her mobile.

[Side Note] Some mobile home parks may not be happy with you moving homes out of their park but frankly it's a part of the game and its the mobile homeowners right to sell the mobile home to whomever they want.

They should break out building value as a percent of total value and use that if they have old enough records dating back to your time fo purchase.

. $150/night average nightly rates in the area), and I assume that they are trying to block certain dates on the calendar.

If a hot tub time machine brought me back to that age, knowing what I know now, what I would do would be:1)  In the very beginning I'd get the absolute cheapest housing possible, be it studio apartment, mobile home in a park, a bedroom somebody is renting out, whatever, and not worry if that makes friends and family laugh and worry about your life. 

They were in rough shape when we bought them and knew that this was going to be an "investment" beyond the closing date. 

Most Conventional loans require a 6-month wait period though from the date you purchased to be able to do a cash out refinance.