credit report for tenant screening

[Steve C.]

I used apartments.com to get credit report for screening tenants. 

I am trying to understand credit report for the purpose. 

Overall score was around 530. 

1. This report I see "verified" date (say recently like 1 week ago) on a collection account. What does this mean? Does this mean that it is legally "verified" that the person is required to pay the amount? This is what I find online. Or does it mean that is already paid? If not, how I do know whether this amount is paid or not?

2. For a collection account, I noticed that it is from T Mobile for amount $3200. I am trying to understand how someone can get a debt of this amount from mobile service provider. Even if stop paying the bill and not paying for a new phone, this amount is something to hard to reach.

3. I see 8 credit accounts which have "negative" line of credits. When I searched, this means that the owner over paid these accounts. Is this correct understanding? Few accounts can have "negative" say when you returned something. But it's strange to me that 8 accounts are like this.