From what I have seen, the typical remedy is termination of the contract, refund of the EM deposit and all expenses incurred by the buyer during the failed transaction.

Let the tenant vacate, and you have one month to find a replacement before you incur any losses.

It's not your fault that the tenant has to vacate, so the tenant should have insurance to protect them against any additional expenses.

Separate accounts per property incurs a lot of overhead, such as minimum balances or fees for missing the minimum.I use separate accounts for each tenant's security deposits.

Additionally, most of the costs to make an asset ready for it's intended business use are capitalized and part of the cost of the asset. 

The seller will lose some rent, potentially incur costs to evict, possibly costs to clean out the units depending on your sales agreement.

Retirement accounts are designed to be invested passively so when the IRS sees you running an active business in it, to level the playing field between retirement accounts and other business the retirement account incurs UBIT. 

In other words, you will incur the cost of demolition just to get the raw land.  

Additionally, do you have any other ideas or strategies that might help achieve his goals without incurring a tax liability?

I know in residential lending you can get a HELOC to borrow a down payment to buy another property. Does this exist in the commercial realm? Current value of paid off property is roughly 350k , looking to borrow 75k-1...