It's commonly done where I am on commercial parcels that have multiple tenants on ground leases, the reason being to create their own tax bill for payment.

Boarding house type rentals are actually pretty common in college towns. 

You also had to pay for an background check before seeing it which while common I fear drives people away.  

What would a common commission in this situation?

You may have your own sewage treatment plant .you will need to buy a large tractor with loader, a small dump truck , lawn equipment , golf carts for employees to get around .Build a house or 2 for management to live in . 

When we took it over we discovered the entire building was infested with bedbugs so badly that our bed bug remediation said if this had happened before heat treatment was introduced the building would have probably been torn down.

Is this common and legit?

There are a lot of ways to do no money down deals but none of them are common or easy.

@Hank Thomas it’s common for them to start with a “desk top appraisal” (at no cost) which means they will pull from their data source to get a valuation (usually very conservative) without going to your property.

With 4 units there is probably some common electric you will be charged for.