You may have a grasp on this aspect, but there are items to consider that can play a big factor when choosing your land such as topography, existing zoning & platted lot status, minimum/maximum requirements such as parking, detention, size of building, setbacks.  

then looked at a recent appraisal and the pool was a -$10k line item in the appraisal. 

My $10k example was admittedly unrealistic.However, by way of further background, @Dustin Heiner wrote an excellent article on this topic on his website masterpassiveincome.com titled "What to Do When A Buyer Backs Out From An Assignment Of Contract".In it he suggests a scenario where the assignee decides not to proceed, perhaps after discovering a big ticket repair item that would cost significantly more than the portion of the assignment fee held in escrow. 

In addition to appreciation potential, there are a bunch of tax benefits to consider as well... my favorite being that a tax loss can be carried forward to offset future taxable income.

I’ll probably take a bit of a tax hit in order to 1031 without carrying the mortgage across.

There are many ways to avoid taxes, so nobody can give you a complete answer without knowing your entire tax situation.If your only taxable item was selling this condo, you would owe long-term capital gains on the $150,000 plus ordinary income on depreciation recapture.

It is a huge ticket item and can eat ~30-40% of my reno budget.Today I did a walk through with plumbers and contractors.

How much term is left, strength of the tenant, rent escalators, rent/sq ft, etc.You also want to make sure you have a good understanding of the roof, parking lot, and mechanicals because in a traditional NNN lease, the landlord is reponsible for these items..and they can get expensive.

So your carrying costs can be quite large.  

I carry around a moisture meter and thermal camera for those very reasons because you never know what a couple of stains could mean behind sealed walls.