However, I would say that your PM is not a general contractor but which needs to hire a qualified and licensed contractor to assess your property.

I would not use the owner to manage your units, it is clearly a conflict of interest as his units will be priority.To increase cash flow and equity ( assuming your units can be assessed without regard of the other units no belonging to you. 2 options: get a professional management company or hire a person smart enough to take the task, teach them what you expect and tie the performance of the asset to their compensationie: filling vacancies, lease renewals, and property accounting, repairs maintenance etc.

Goood job on assessing the age on your own .Hopefully the deal is still worth it to you. 

It's also a lot easier to assess which neighborhoods are worthy of investing in.

Most of their assessment will be based on your tax returns, bring 2 years tax returns. 

And if I hire someone to assess my home, will they look at the inside?

Need to get a Capital Needs Assessment / Property Condition Report 4.

Drew - in my opinion, Micheals assessment is spot on.

My concern is if a property has significant appreciation since the last time is was assessed for property taxes, then when I purchase the property, a red flag pops up for the city since it was purchased at a higher price than last time then they reassess, and then the property taxes increase significantly. 

From there I would contact a couple of plumbers and have them assess the scope of work and provide quotes so you can choose who you feel the most comfortable with.