You might not be adding very much value.

So I'm curious if all of these items on the list in the book actually need to be added into every investment property, or if some can be omitted depending on the property.

The buyer would be added to the deed. 

Since profits made from wholesaling are counted towards ordinary income- would I be adding the $46k from my w-2 to the $39.4k (before JV payout) OR the $29.2k (after JV payout).

It seems the repayment of principal should be added to the annual returns as well as appreciation.

Would I need to be added to the deed with a quitclaim?

Are you creating a separate entry to that unit from outside, will you be adding a kitchenette (or doing a communal kitchen in one of the other units, which would diminish the value of both), does the attic have proper ventilation, are you adding a bathroom or has one already been added in the past, will it have it's own hot water heater, are you adding an electrical and water meter, or will you be paying for the additional usage? 

Always a choice here, but if closing costs of old loan are paid back in X amount of years and value can be added, refi to pull equity out.

You as the investor should be adding everything you listed above.

Try searching "Housing in Seattle" and see if you can find any groups; often, you will have to request to be added into the group.