I think the biggest issue of the rental properties transfer into LLC(s) is that I have to get consent from my mortgage lenders.

Again, is this proper to do without one owners consent?  

Tenant shall not allow any other person, other than Tenant's immediate family or transient relatives and friends who are guests of Tenant, to use or occupy the Premises without first obtaining Landlord's written consent to such use.

Also the buyer knows that the previous price of the property was a considerable amount less than what he/she is paying, and the title company is making all required disclosure to the mortgage lender funding the transaction.As a licensed professional it's illegal to advertise real estate for sale without the owner's consent.

Could Nathan still get the authorities involved without the new owner consenting?

As a result, any person occupying with the consent of the tenant is in lawful occupancy and is not a trespasser or squatter, regardless of whether the landlord is aware of the occupancy.

I know this is an year old thread but I am trying to understand how the beneficiary can change without the original beneficiary's consent if he still alive?

Buying a note, from an institution, you won't unless they offer it along with other to be sold, that is not a trustee sale, a trustee sale is a foreclosure on the collateral, the property.If you want to buy a note, a single note prior to or in lieu of foreclosure, you will need the borrower's consent.

Even if they were trying to flip their position as the assignee to another investor there is a clause requiring written consent from me to do so.  

Also, your lease should have some clause about them adding fixtures or changing/upgrading without your permission, so it may actually be her responsibility to pay to have the cabinet removed, not your responsibility to reimburse her for it, I would think, if she did it without your consent and you have it in your lease.