They will not provide you that documentation.

Is it a reputable company and will the documentation provided from the study hold up in an audit?

Seeing as they are the owners I would think their name would be on those documents.

Should I require all four individuals to submit rental applications and undergo background checks?

There's only about 2 types of work permit I know: closed  vs opened work permit: where the former has a condition of which employer the holder of the permit can work for (it's specified on the document); while the latter does not have that condition; hence, the holder of the open work permit can lawfully work for any employer.

My go-to response is always: Do you have a Move-In Inspection to document the home's condition beforehand?

I am no professional here, just explaining from my experience.. first, insurance starts claim and they send adjuster out to assess, check damages, and collect documentation.

I suggest submitting offers where the numbers work today.

We use RentRedi for tenant screening and management, lease documents, automated late fees, messaging, maintenance requests. 

Some company paystubs have specific characteristics that are embedded in the document that make them a bit different.