If you take over their accounts (which is a violation of terms of service) and they find out, you will get those account banned and lose it all.I would work hard to start over and get those bookings over to your new account.

They have already violated the lease by moving people in without your permission.

If a lender violates this provision and does not correct the violation when it is brought to the lender’s attention, the lender may be subject to significant penalties.

It is a license violation for an agent not to pay off a court judgement.

Make sure you check your state and local laws before making a final decision as you don't want to violate state and local landlord/tenant laws.  

You mention 1031 so I will say: in a 1031 you never hold the proceeds from the sale in your own account, that would violate the rules of the 1031 

I found this info online:Circumstances that allow you to avoid having to produce documents or appear in court may include the following:Claims that the information sought is privilegedIf you lost or no longer have the informationThe produce or appearance violates your Fifth Amendment constitutional right against self-incriminationThe request is overly broadThe request is unduly burdensome 

If gone unaddressed, complaints can lead to costly violations & fines.

I don't want to violate any rules but my brother got this exact HELOC and I'm about to get one for my first purchase.

You've probably heard of big Landlords losing property, but only because they were flagrantly violating Fair Housing, running a slum, or otherwise violating the law in an egregious manner.