Nope.... the rent is for the unit..... not the number of tenants in it.

Small-town vibes can be gold for Airbnb, but make sure there's demand.

Can anyone tell me what I should look for when I want to buy commercial an apartments contained of 5 units or more?

There are tons of opportunities, but the niche of San Diego tends to be purchasing small 1-4 units and adding ADUs to increase density (if that is a strategy you are considering)

Lenders generally require you to have at least 3 months of reserves or cash that will pay for mortgage, property taxes, insurance and HOA (if applicable).Most lenders will generally lend on 1-4 units and condos.

Another consideration is a 1031 exchange to a multi family unit.

Is an ADU (accessory dwelling unit) in option for your home?

You are actually quite fortunate to be considering buying a multi-unit in Chicago.

I also cannot imagine companies with hundreds of units getting better than 4.9 out of a 5 star rating. 

You can trade that into the US for a 20+ unit