If the answer is yes, then Opportunity Zones both enhance the potential for your own balance sheet, and allow you to redeploy capital from other investments.The two greatest unknowns that concern me are the duration of the investment for tax free gains, and future legislative changes that can dramatically alter the policy.

Instead of splitting the land and selling off the dirt and paying off the note, I would like to keep the financing in place and let the rental cash flow, although I realize that is not possible given the asset will be altered.  

But can anyone refer an investor-friendly lawyer to look over and alter contracts?

I too was first deliberating whether an early termination would alter the original "expiration" of the lease, as per your interpretation of "expiration".HOWEVER, if this was the case, I cannot think of a scenario where the condition expressed in the halfsentence "... but not ... earlier than 60 calendar days prior to the expiration of a fixed-term lease" would come into effect.

Commercial use should not result in significant alteration to the property or one which could not be easily converted back to residential.

A lot of management firms paid attorneys to write their agreements and might not feel comfortable altering terms.

We did know he had made alterations to the unit before we closed.

CPA's, Tax advisors, Landlords and House Hackers are more than welcome to chime in.Here are the questions:  Since there was an existing system (that will be pumped, crushed, and abandoned), would there be a difference (deduction/depreciation-wise) if this is considered and alteration vs an install?

That would alter your numbers. 

On larger properties, outside of performance calls, owner's usually get involved if there is a big bust in the budget (to alter the business plan if needed), capital expenditures are going to be more than estimated (find ways to cut costs if possible), or leasing strategies need to be adjusted to keep up with other competitive properties (example: providing concessions on new leases or renewals).