@Scott Anderson  your correct this buyer is new.. and does not realize that investors dont look at income property the same way a homeowner does.first thing drive by if it looks good at the curb make offer.Only go into the property when your with the home inspector.. thats the only time you need to see the interior. 

@Karl B. has good suggestions.Make sure you get a good home inspector!

However, if you move in and it doesn't work out with this people (and it will NOT work out - you can already intuitively see the writing on the wall despite your being new) it will be a lot more difficult on you and your family - not just emotionally, but financially - as these kinds of people don't always go quietly.I think @Jay Hinrichs idea is brilliant - just explain that the only way you could get financing in your situation is to receive the other unit vacant to do "necessary renovations" at the recommendation of the bank's inspector. 

I'd also suggest getting a second opinion, both from another realtor and inspector.  

Become a property manager, real estate agent (commercial), appraiser, inspector, mortgage broker, etc.

Get a property inspector if this is your first deal and ask him to look for all the property's defects and also the deferred maintenance items (or things that will break down in the next 12-36 months that you need to budget for)4.

I know you can get inspectors but I keep hearing how you need to jump on a deal quick.

You might want to talk to a building inspector or the planning department. 

On the second attempt to do inspections I’m standing in the front yard for over an hour with HVAC and home inspectors waiting for her to show, power not turned on, water not turned on and no access to unit.

If you are really worried about it you could invite the building inspector over to tell you if you need a permit.