A SFH in that area is going to be pretty tough.

Like you will pay them a certain fixed amount each month, in exchange for doing all general repairs for just the cost of materials.

Make sure each part of the job is itemized also try to separate out labor and materials if possible. 

You can determine the NOI from a brokers marketing materials, then when it sells follow up and ask what it traded for. 

I recently closed on a duplex in New Jersey and will need to start purchasing materials for the rehab and wanted to see if I could charge those expenses on my business credit card.

If not, a trip to city hall would be the fastest way to get an answer about your specific property but I'd say you'll need a variance to get permission to add a driveway which in Jersey its may be a tough task.

It was a little tough investing in another country.

knew more about the history of construction materials and replacement timelines, would have saved me $20k on my first rehab...had to replace ALL of the plumbing and electrical when I hadn't planned for it.

For example, how would an apartment building lose its value in a market crash, and be tough sell?

Of course, I bought the materials.