If I find that two of the units in my building have bed bugs infestations, it is necessary to have all the remaining units and common areas in the building also treated for bed bugs? 

Lawn / Snow / Pest Control -- who's handling?

But, at the same time, there are so many things to consider if you are going to pick up a 12 unit building like how much of the utilities the owner pays (and in winter heat and hot water will take a bite out of your net), that the owner is responsible for all common areas (lawns, snow removal, pest control, common area cleaning, etc), and the amount of involvement required by you (approving applicants, approving charges over a certain amount and actively researching ways to keep those costs down, etc). 

Maybe a "pest inspection" might be something that you had to pay for out of pocket...things like that.  

I know what you’re thinking, “This guy is a pest.”.

I know what you’re thinking, “This guy is a pest.”.

A bedbug infestation?  

Don't want to be a pest but I'm not sure if the PMs are working for me.

With our last unit, we did have a small pest problem.

Also, whenever I have a pest problem, I hire pest control companies under contract for a while, and hire licensed contractor to install window air conditioners, etc. areas where tenants can sue you if not handled properly, such as an AC falling from a third floor window.