I would recommend this rather than splitting the bill and trying to collect that amount each month. 

Couple the two together and you have a receipt for tenants that cannot afford to live.As for trying to collect, you should ALWAY put them in collections for two reasons. 1.

I want to know if I buy a four plex under an FHA, claiming that one of the units will be my primary residence, can I move somebody into the unit I claim as my residence and collect rent from them without issue? 

You can invoice them monthly and collect like any other vendor. 

I want to purchase the properties, set up everyone on a month to month lease, transfer the utilities to tenants and eventually raise the rents and collect deposits. 1.

The due will be time/effort collecting.  

These areas have much more active management of properties with more collection issues, more turnover costs, more vacancy, etc. 

Who’s collecting rent and dealing with the tenant?

Consider all of the services a full service short term rental property manager offers: marketing the property on over 50 websites, taking professional listing photos, optimizing rates to maximize revenue, manage all guest interactions from inquiry through checkout, manage all maintenance issues, collect and remit city and state hotel taxes and manage reviews.

Collect an IRS Form W-9: Before paying a contractor, collect a completed W-9 form from them.