You are definitely not dense. This is a complicated situation, there are a few special circumstances for a rental property involved.
In your case, enter “yes, you owned 100%” on the screen labeled “Property Ownership”. Although this is not true in regards to the ownership of the home, but it is true in regards to the income from AirBnB.
You will then need to make the calculation for the rental portion of your property (number of rooms rented/total rooms in the home) as mentioned in the revision to my original answer.
TurboTax will use the number of days rented that you enter on the screen labeled “Was This Property Rented for All of 2016?” to calculate the portion of your rental expenses that are deductible for the portion of the year that you rented the property on AirBnB.
Let me know if the above makes sense in a comment. I am off for the night in a little while, but I will continue if needed tomorrow night with you.
(I am going to paste a few attachments to the original answer)
