H&R Block software prompts me: "When you stop using a property for income, if you didn't sell the item, you may be able to write off any remaining basis" which then refers me to fill out form 4797.

The Zoning Code rules and regulations for (D)ADU and Duplexes can be found here, Chapters 5-7. https://everettwa.gov/762/Zoning-CodeI haven't spent much time reading the Zoning Code yet, and will likely visit the zoning office to walk through items of interest as the need arises.

As I alluded to me in my first post, I made the typical rookie mistake of looking at the home and ignoring that many items were on their last leg.  

You can always upgrade single items later if you feel you need to, you can't really downgrade...Also, have a plumber install your plumbing if you're worried about flooding...plumbing and electrical are risky to DIY.

do you find it strange that year to year expenses are identical down to the last dollar though the inputs swung significantly year to year on some items?

The itemized expenses are $12,000 a month against $8,000 of gross rents.  

I Keep a written daily mileage log in a bound book in pen if driving, and then keep all the other receipts and itemize them into the correct travel categories when I file.  

Size: Above Ground 1,660 sq ft/ Unfinished Basement 350 sq ftI'm looking to update below items: Exterior: New roof and window (as needed)Yard: Cut big 2-3 trees in the backyard, clean front yardInterior Basement needs mold remediationNew kitchen (cabinet, appliances, & etc)New Bathroom (2.5)Move/remove walls Add ceiling wallAdd insulationelectrical work (if needed)plumbing (as needed)new paintNew floorIt pretty mush needs a complete renovation.

You go over the appliances and check out each item that works and have the tenant initial it.  

(I itemized it at retail value on a list I gave the appraiser for a refi.)