I do not think that it is required .. but in our Property Management Company both myself and my boss are licensed realtors but we do not compete with realtors as we rely on them for referrals of Investors.  

Before you buy, make sure to get the latest rent roll (a breakdown of what tenants are actually paying in rent), the tenant ledger (which shows their payment history—whether they’re paying on time or carrying a balance), and of course, a copy of each lease agreement.Too many investors rely on what the seller says, which often doesn’t match up with what the tenants are doing.

Which if youve done flips , but not commerical multi before, you wont miss much,  however a 6 fam is a commerical code permit so there are slight variations between the residential code for essentially all trades which if you dont have a detailed plan and you dont double check every code before you do anything but rely on cheap labor to do your due diliegence for you, what could go wrong ? 

I'm helping an investor right now who has been living out of state, and has been relying on his "handyman" for all repairs and such.

When I was in Michigan, we could vary the deposit based on credit worthiness.

While you are correct that you’ll be relying on your purchase of the replacement property to go through, there are a few strategies to use and language to add to the PSA to try and keep a seller honest and protect you as buyer.The attorney negotiating the sale and purchase should hedge the risk snd build in flexibility on both ends.

Always get monetary concessions... never rely upon a seller to do anything after closing, unless you want it done half-assed and on the cheap.

So, the real answer to your question will vary from city to city.

The loan options vary by state.

I could be wrong and this could also vary from state to state.