My company has non real estate (automotive related) operations in CHA/ATL/DFW/TPA/NSH/PHX, but I have family in Nashville and have grown to love Florida in my travels.  

For STARTERS we don't know if we should open an LLC together and start to buy properties with private money via LLC OR if we should each get conventional loans independently (tenants in common) with an operating agreement in place.

Tenant-does this operator/franchisee have multiple locations or just this one, is it personally guaranteed?

If you want the protection from the LLC, make sure you are operating under it.

I do travel fairly often back and forth but day to day operations are handled by my immediate family.

I have two questions:What should be in our Operating Agreement (partnership)How much, if any, should my siblings rent be now that she owns 1/2 the building

It is not appropriate or prudent to be operating a business with out first learning all your state regulations.

Many apartments are pretty small mom-and-pop operations, though.

Anything that is left over after paying for the down payment, closing costs, operating expenses, mortgage payment, credit card interest, etc is cash flow.

All of this is with me running a 10% vacancy (plus the additional economic vacancy created from me not paying market value for my unit), 30% for operating expenses, and at the asking price.