Some advice please?

I'm moving to Thailand next month and renting a condo at Centric Sea. The condo is owned by a friend who recently passed away but left the condo in his will to my cousin who resides in the UK. We are currently going through the Thai legal system to have the property transferred to my cousins name.

I intend to apply for a residency certificate but I only have a rental agreement drafted by my cousin who is not yet the owner until late September /October after the court hearing. I believe I need this certificate to assist with opening a bank account, visa extension (12 month) and driving license applications.

My concerns are that when I apply for the residency certificate my cousin has not informed them of them of me moving into the condo and risks either her, or both of us being fined........?

Can someone please advice me of the best way to approach this as I wish to try and avoid any fines to myself or my cousin?

Kind regards and thanks in advance..