How do I safely partner with someone on a large multimillion-dollar apartment acquisition as a passive investor? 

New Western Acquisitions.

We help tote the Note with JV partners in acquisitions of investment properties under our management.

From those relationship build a core team that allows you to execute acquisition & business operations.

An investor works really hard for the initial acquisition process for the lower purchase for the larger pay off of the re-list.

@Aaron S. it only makes sense when you can acquire another property, safely service your total debt (after refi & new acquisition), have adequate reserves (ie to protect your investments) and increase your total combined profitability.

So I am currently working on a deal that has two tenants in place who only pay $500 a month (no lease just verbal agreement). These rents are far lower than the average in the area ($750+). What actions do I have to t...

What is a common way to structure a partnership like this when it comes to equity splits, management fees and acquisition fees?

They can do well in real estate as tradesmen, learning the acquisition and finance side as they go. 

Depending how you set up property management and the business of acquisitions and trading properties will determine how passive this income really is.