For instance, my dad rented space to a barber shop, and over the span of 25 years, to a succession of barbers.

No matter how relatively cheap houses become in the next 2-5 years, those with chronic unemployment or underemployment over that time span, will not be buying them.

Do I need to be in state during the entire span of the flip?

it does look load  bearing but depending  on the span from the support on the right to the  wall you  might be able to put a beam all the way across  the span i think maximum beam lenght  is like 21 feet 

It helps with SEO organically because of YT's ties to Google.Keep in mind that while some people use Youtube, the attention spans are getting shorter each day.

For this reason, I schedule my showings on the same day and in the same time span.  

We have a combination of camera motion sensors, road sensors and linear motion sensors (cover up to a 300-foot span). 

20 years is the typical life span for roofs and mechanicals, so if the house is 20 years old, you may need to replace those, which could add $7-10K to your rehab costs.

If you want a lasting repair, your best bet is to cut out a section of the drywall and put in a new piece that spans a few studs on each side of the crack.Cost: patch job should be $30 to $50, or more depending on your negotiating.Cutting out a large section and putting in a new piece would probably be $150-$250.The wall texture will also determine how good the finished product blends and how long it will take.

@Ryan Steele yes he did!