However, my current tenant claims that the garage door repair should be considered "wear and tear" and, therefore, my responsibility as the landlord.I believe there's a distinction between normal wear and tear and tenant responsibility.

Almost no lender will give you a 2nd home or primary loan where there are not two distinct living quarters if there is a 1031 involved. 

Weds to distinguish himself from all the others, distinct guise himself to those who only make money when a deal is done.

The primary distinction, in my experience, is the one-bad-apple problem- if you get a bad resident, you must take steps immediately to prevent that resident from chasing the others away or souring them to the building and reducing future referrals.To your question, I suggest looking at each unit and determining the fair market rent for each one.

Am I wrong to make a distinction between these two costs? 

@Jeffrey Donis that's a good point...I guess we don't tend to think of the two individual cities because people reference them together so often...but you are right, they are 2 distinct cities. 

(Think of this like a payable on death beneficiary on a bank account.)This deed has 2 distinct advantages: (1) Stepped up tax basis and (2) immediately owned by remainder beneficiaries upon death.

It will be it's own distinct tax paying entity.And because it is now the tax payer for the property it will have to be the entity that sells and does the 1031. 

I like to draw distinction to yield as cash flow opposed to [total] return.

@Jason FarmerThere is a distinction in the type of lead (but not related to what you label it):1).