Most important advice I'd give to anyone trying to decide on the best path to invest is to be very honest with yourself about your goals, strengths, weaknesses, time & risk tolerance for the investment you are looking to make. 

What are your strengths?

Help your wife to see your strengths and respect them. 

Situations are highly dependent on your background, network, and your strengths/weaknesses.

You finally decide what you wish to do...dive into it..become obsessed...don't get caught up with what everyone else is doing...perfect your craft, focus on your strengths..and when your considering ways to increase the service you provide..use your marvelous mind to visualise into the future and figure out how your fields business will be conducted in 10, 15 years.

Stating they must registered per state law and locked up may offer some additional strength to any clause you have on illegal activity ( if you are mainly after illegal activity).

Each partner should adapt to determining what their best strength is.

I agree with @Stephanie P. you need to find your strength and what you enjoy.  

Keywords such as COCR, IRR, CAP Rate, DCR, Equity, Debt, Debt service, yield penalty, terms, amortization and other weird financial terms that you will need to understand to evaluate the financial strength of the dealWHY should I invest with them - this is wher you define your goals and make sure the current offering match your goals.

Bottom line its good your recognizing your strengths and what would really worry you.. and there is so much to real estate buying a single rental is just one of them.. albeit the most popular because its the easiest to do for most folks and the least complicated to understand.