If I do the rent the whole duplex to them, I was thinking of $1100/$1200 per month and it easily rents for $1850 combined.

That's a piece of great advice, which is easily manageable.

If they are professional, they can explain this quickly and easily.

Easily remedied in a weekend. 

Personally the cost (in Chicago) to have a structural engineer evaluate the property is a deal breaker for me.

It seems to me all the other info can be gotten (or easily researched) as soon as the lead comes in.

I’m still evaluating options.

My family said, "I'm doing too much and moving too fast" I just get bored very easily after I close a deal, so all I can think about is when I will buy another deal.

In my state the form itself is not required by law, but it is required by law to disclose "in some way", any major defect that may not be easily visible to the buyer. 

I read about this in a blog article recently: https://www.biggerpockets.com/...Bonus Tip — How To Cheaply Transfer Property To an LLC"...you can easily avoid triggering a due on sale clause by using a land trust instead of a direct transfer.