He said this happened after he signed a new lease so he didn't update it.

If the seller refuses to sign, you'll have to send a demand letter.

For the most part a team is just an agent and a property manager if you buy turn key, maybe throw in a contractor if you are doing rehabs, but in general yes you should know who all these people are before you sign on the dotted line if you need them.

So I have tenants that haven’t signed a lease yet, but intend to in order to move in June 15.

We swallowed our pride and offered them May's rent back and they leave withing 7 days as long as they sign a mutual general release. 

Could the broker sue you for violating the contract you signed with them before you took your exams, oh yea.  

A lender will want photos of the inside including the breaker box and any visible damage, like holes in the drywall or signs of a leaking roof.

This is where you see the signs telling you they pay 1% on savings accounts. 

Have her sign a release talking about the deposit, date she left, etc.

I am in Florida, which is a super lien state, so I would assume a number of these MAY have clear title depending on the year the mortgage was signed.