My advice, make sure the roles are clearly spelled out in an agreement that is signed by all parties involved.  

and how it looks if you or they want to move out before the other (with you as owner, you cannot discriminate when you place new neighbors for them).Still use a rental agreement, and give both parties an easy out if it isn't working out.  

We are considering a property with two commercial spaces and two 1/1 apartments. The realtor just told me we need 50% down. Has anyone experienced this and are there any other options?

Also related to this property -...

I'm excited to get started ASAP after I get married (in March 2017) and plan to start with a multi-family unit to occupy and rent out other units simultaneously.

I've lived and worked in NJ all my life, Construction for 30 years, built sheds to custom multi million dollar homes to light commercial work. pricing is all in what has to be done and what goes into the project.

The hard part is getting visitors to your site.

You managed to get your first property without any money, by working out a deal with third parties.

I'm looking for multi-families in the St.

If you have a multi-fam of 5 or more units, you can occupy them as an owner.

I would recommend finding a solid Multi to house hack with, and then start flipping.