One thing to keep in mind if you do rent is the type of clientele the units will attract and if you're comfortable working with that type of clientele. 

Or is there a way to figure out a comfortable guess.3.

You'll also want to have an accountant and attorney.For your team member, you should work with those you feel confident and comfortable working with.

But it made us more comfortable knowing the legal guy told us we were all good!

The grad student who has leased the place did need his parents to co-sign (and has a healthy income from scholarships and a teaching assistant position) so I feel pretty comfortable there.

You can always hire a co-host to help you until you get comfortable.

I'm big on leverage so this might not be for you but..Depending how much your primary has appreciated, I'd take out a HELOC.Use HELOC to fund the duplex house-hack you mentioned, then rent out your current primary.Depends on several variables of course and how comfortable you are with your finances, but that is what I would do.

Really stepping out of my comfort zone in trying something new for my family.

Like any business, they will make decisions based on what's best for their business and maximizes profit. 

One of the clearest places I can find great deals to maximize money made into a deal is the foreclosures market - but it seems fairly confusing to navigate.