My vacations were "staycations" where I spent a week ripping up rotted floorboards or tearing out toilets and tubs.

Either from infill lots, raw land, or tearing down an older house?

That is not normal wear and tear.

The "normal wear and tear" thing confuses me too.

We start by asking about whether the tenant paid timely, kept the unit neat, was cooperative and flexible when the landlord was showing the place to new tenants and kept wear and tear to a minimum.  

Section 8 is great but just be prepared to deal with the occasional routy tenant and extra wear n tear on your properties.

If you miss renting to students around August 1 or before, you may wait a long time.Also college students tend to be pretty rough on wear and tear of the homes, so you want to budget for that. 

I am risk averse and if I were to purchase, I would tear down to the studs and do a full rehab {this would include getting rid of asbestos shingles and insulation).1) I have done a ton of research and it appears as if getting rid of asbestos is very DIY able assuming you spend money on the safety equipment and use it properly. 

In our case we did have recent damage from severe weather but with PLENTY of wear and tear. 

Would appreciate some helpful advice on what you look for when determining whether to tear down and start over , or to bite the bullet and rehab best as possible.