If/when it comes up within tolerable levels for humans, it's on them now.3) If it comes up positive for dangerous mold: now you have a health hazard that would have gotten worse over time.

However, I did speak with the realtor, and she sent me information on key items like the water heater, which was last replaced in 2014.

I don't understand why my taxes go up a few bucks when I change move an item (a kitchen appliance) from bonus depreciation to an expense on schedule E.

Because I pay for the materials, I know the cost of each items now.

Another item to factor is cost.

.- Stocking Essentials: We make sure that all necessary items, like toiletries and linens, are available for guests.7.

Remember, the notion of amassing wealth without investing is a dangerous myth perpetuated by self-proclaimed experts.

I only recommend this route if furnishing the STR is not the long item.  

So you telling others that  "it works" while thousands are trying it while 90% of the people trying it fail.You are pushing opinions, disguised as facts to others and that is not only dangerous, it is wrong and misleading.

But if the replacement property has less value in section 1245 items, you do have to compute the difference (which pretty much requires a cost seg study on the acquired property), and then you have 1245(b)(4) recapture on the difference.