Be wary of front loading on the itemization/draws in the contract. 

Alternatively, are there some ballpark estimates for each expense item (e.g., 8% for vacancy, 3% for capex, etc.) that can be factored in as realistic or worst case scenarios when analyzing the deal?

Firstly, the real item is only a question of Point of Production.

They also sell items at farmers markets.

Now for the house you are leaving behind…I like to have this one freshly painted, and take action on any maintenance items.  

@Francisco PineiroYou could call a few home inspectors in the market you are investing in and see if they do draw inspections so you know the items are correctly done before sending funds

We removed a chimney to open up the space and updated all the major ticket items—new electrical, HVAC, and roof.

The floor area is to be calculated on the basis of total dwelling unit area.Thank you for making some excellent items to consider going forward.

Lastly is structures, and to be honest I think we'd probably have to move the needle $100k or so on that item because I have a feeling from what I've seen thus far is these structures are not of the most durable enduring type and I will have some considerable cap-x over 10yr window on them.

Lots of posts here on BP on all the questions to ask as there are 100+ items to consider