However, lenders have brought to light that state laws prevent them from charging me what they would need to charge me in order to finance this as an investment mortgage.Purchasing it with a conventional mortgage as my primary residence would work (I don't currently own any other property), it is not what I am trying to do here.

Kevin,I've looked for multifamily properties on the MLS on and off for two years while we saved up our initial investment capital, but I've never seen one posted that was in "beginner's shape", so to speak; always large issues with the properties that would either require more starting capital to repair than we have or will be able to leverage, or otherwise have issues that prevent conventional financing.  

Is there some gov regulation preventing it?

My thought about having separate lease agreements (Bedroom A, plus use of common areas, and Bedroom B, plus use of common areas) was to prevent my son from being liable for his housemate's rent.  

In came legislation and HOAs to issue fines and beat you senseless with rules to prevent any real profits.

@Wayne Brooks I'm likely going to have to go that route on closing day if neither have been done, but I'm just trying to find way to prevent that. 

Is there anything that I should be aware or take precautions to prevent these things from happening.

There is no way you can legally prevent investors from moving in on the list you provide them.

This will funnel into the shower base to prevent water from leaking down the walls and outside of your shower.

This has happened three other times.I have notified the tenants to make sure they don't just throw raw trash into the bins without bagging them up first, or to not throw in tall objects like a stick which prevents the lids from fully closing, then the odor draws the creepers to the bins.