Hardly anyone can prep properly, mask or dropcloth properly, cut in around trim and windows, get even coverage, etc. 

The first house that I bought was 17 years old, 3 br, 1.5 bath, brick ranch house with hardwood floors, Andersen windows, ceramic tile baths, gas heat and a brand new roof. 

If your LOI is accepted and you are give your window, you would need to use a way more comprehensive analysis tool.

She once threw a full 40 ounce beer through the front window on the house.

You have 22 properties that are probably at least 60 years old. 15% maintenance of $1000 rent does not get you very far when you start looking at big-ticket items like roofs, windows, plumbing, HVAC, driveway, tree-removal etc.I am doing this long enough here in Milwaukee that I own some properties I have rehabed twice.

I use eggshell on the walls, flat only on ceilings and high gloss on trim and windows.

Gathering as much info as I can in the short window of time I have. 

@Jorge Caceres I don't normally monitor for open windows but had another tenant mention it after which I did.

If you're not resident in Japan, you can't borrow from Japanese banks, and so that's out the window. 

They can't assess all the subjective data like overall layout, view from the living room window, the dogs next door that bark all day, the width of doorways, size of individual rooms, quality of kitchen cabinets and appliances, etc.The best thing to do is study your market regularly.