In all honesty, it's more common for me to see vacant homes with basement walls needing EXPENSIVE repairs due to poor landscaping and/or improperly installed gutters.In short, I'd say keep your options open regarding vacant slab homes. :)

The best thing I did to stop a lot of the BS headaches was to install cameras throughout the halls & common areas, it was like someone threw a switch, the cameras went on & the BS went off, it was amazing.

I was thinking of installing the carpet first in order to have the living room and bedroom liveable and then install the laminate while I live there. 

Good tenants aren't going to want to stay in those really bad areas except ones that have no choice.If this is a larger complex installing a fence around the place and an electronic gate at the entrance helps keep criminals out.

No mitigation needed except to install gutters on our unit (paid by the association).

I am looking to make a rule of thumb of when each material is used.I've installed around a hundred better-quality, custom-fit vinyl windows so far.

You can cut cost down by installing carpet in the bedrooms.  

Our higher income houses are actually great once installed (I work full + time, run 9 houses and am launching a blog/webstite,  + have a husband so I know busy) Than buying another personal property with 5% down conventional.

. ($2k)No appliances provided, so new appliances should be installed. ($2k)A few smaller odds and ends with broken cabinet doors etc, but fairly minor. ($1K)That's probably at least $15-20k work there.

It will generally pay for itself in 2 - 3 years for a self install and about 4 - 5 years for a professional installation, which will look  a lot better and last much longer.