If it helps, this site provide an overview: https://www.nolo.com/legal-encyclopedia/overview-l....

However, unless you like the hustle of wholesaling or don't mind sweat equity in doing rehabs but the tax implications are not worth it in my opinion and there really isn't an end. 

There may be some advantages of having it set up as an S-corp if there are self-employment tax implications.

Any Dodd-Frank or other nanny-state nonsense legal land-mines to look out for here?

What are some legal aspects of investing in Milwaukee that are the most challenging for investors?

To reach and understand the tax implication of each property, prior to buying it.

A realtor uses a standard legal contract that licensed agents are required to use in Utah. 

I currently made an offer on a legal “duplex” that is 3/2, 3/2.

Others are more savvy with that stuff than me. https://www.nolo.com/legal-encyclopedia/overview-landlord-tenant-laws-illinois.htmlhttp://www.ilga.gov/legislation/ilcs/ilcs3.asp?

In Dodd Frank, they anticipated that some might carry paper to get around Dodd Frank (not that you are doing this) and therefore they also "cast their net" over seller carry backs.Most importantly, please don't rely on what I say, except to inspire you to seek legal advice (which I am not qualified to give) from a qualified attorney in this area, and structure this so it doesn't get you into legal tangles or possibly worse, interaction with the CFPB.