However, the market has changed in that time period with interest rates changing and homes staying on the market longer and longer.You mentioned the big ticket mechanical items for the house, but it sounds like paint, flooring, kitchen and bathrooms we're mostly untouched.

I look at every single item in the pro forma and imagine that it is complete BS, and see if I can challenge it.

Will ask them to send me the itemized closing costs / loan points details etc. so that I may compare.Thanks @Jay Hinrichs for that.

We own a restaurant building in Downtown Phoenix, and my tenant is having a horrible time with indigence hanging out or parking there at night and leaving dirty diapers and other items.

However, he still has some items (TV, bags) in the garage.

Some PMs know they aren't good at handling (or don't want to handle) certain items. 

Is a store like Home Depot the spot to get these items?

Start by itemizing the expenses and send them an itemized invoice; include unpaid rent, utilities, etc. 

If you go the AirBnB route just make sure you go all in - don't skimp on furnishings, design and amenities - so give yourself enough room to purchase these items.

Not allocating cap ex and maintenance because an item is not expected to fail soon is simply providing a misleading return estimate.  10% maintenance/cap ex ($132) is less than half of reality and maybe less than 1/3 of reality.