I recently looked at a duplex and wanted to get some thoughts on if these items should be factored into the offer price:The water heaters were over 10 years old, both gas furnaces were over 10 years old, the water was not separately metered, the front porch (cement) had some cracks in it, and both units would need some paint and new carpeting. 

I don’t have all the details yet but wanted to see if anyone can point me in the right direction.

(But I am in California) send  a note describing items to the address you last have for her (I like the update advice given above) and give her the state allowed time.

You can select what info to purchase, but basically you are getting the property address and details of the home as well as last sale price.

I had to explain our reasoning in detail to a number of potential lenders. 

They are working out the details now.

Also, Airbnb provides some details on short term rental regulartions by city under the section entitled "Your City's Regulations" on this webpage: https://www.airbnb.com/help/article/1376/responsible-hosting-in-the-united-states

I would check the big items (Water heater, HVAC system, roof, windows, appliances, etc.)

Send me a pm with the details on the house 

If you do pull it off, post back with details so we can all learn. :)