Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.

Check big-cost items more carefully.

Ideally something that is on web/app that'll allow me to keep track of different items come tax time. 

I can't say the tax balance is completely incorrect because A LOT of items can affect this number.

This is a big ticket item.

From what you have posted this isnt a demanding tenant issue... this is a "you didnt inspect the property very well and fix all the needed items BEFORE the tenant moved in" issueIf your PM is responsible for the post move out and pre-move in inspections, then they did a crap job.

How dark do you go with cabinets and others items you mentioned?

Tenant’s failure to maintain any item for which Tenant is responsible shall give Landlord the right to hire someone to perform such maintenance and charge Tenant to cover the cost of such maintenancePremises defined in the lease as follows:  Landlord rents to Tenant and Tenant rents from Landlord, the real property and improvements described as: address of the rental property (“Premises”).1.

Income requirements in underwriting a lease is NOT a housing item, it's Commerce. 

As you run your business, you may have to buy a new roof unexpectedly, or replace the hvac system unexpectedly, or replace kitchen items on a turn because they've been destroyed or reached the end of their service life.