I will second @Ryan Thomson, there’s a lot that you went over in this post that is a lot to take in and is a visual that you have thought a lot but are also all over the place.

I posted about my first ADU project in San Jose back in 2019 and shared 3D visual, pictures and numbers if you are interested: https://www.biggerpockets.com/...Building an ADU could be a daunting task and takes a lot of $$ and effort.

It will probably help you visualize the parts of the process if you ran a few made-up scenarios through the calculator.

I'm having trouble visualizing the journal entry for this transaction. 

We added landscaping and added red to the front door to add visual interest.On some units we kept the retro finishes, but this one had damage to the tile and stains on the porcelain that couldn't be removed.

Before dismantling the toilet, put some food dye in the tank wait a few minutes for the color to disperse and then visually inspect the bowl to see if any of the dye is coming thru into the bowl without flushing the toilet, if you see the color in the bowl, time to change the flapper or entire flush assembly.Also, check all the interior and exterior faucets/spigots.  

Your home inspector should be able to give you a good idea of the environment under the house along with a visual of the pipes.

Do you use the visual checklists and before and after pictures that Properly is able to do? 

The screen is acting as a visual barrier to conceal the brick to give the glass a blacked out appearance.

It sounds like you are selling a with a future home on lot which is a lot more difficult to sell because people have a hard time visualizing the home.