@Zhenyang Jin A DBA is generally not necessary for your LLC in California unless you plan to operate under a name different from the LLC’s legal name. 

I will send you a copy of the agreements that I have and they are legally binding. 

(this was Upset Sale where all liens transfre to the new owner.)I am not an attorney, nor an accountant, nor a CFP, nor a doctors and am not giving legal, accounting, financial or medical advice.David KrulacBigger Pockets Podcast #82

Maybe just say you will pursue legal action if the situation isn't immediately addressed.

https://www.biggerpockets.com/forums/51-tax-legal-issues-con...

@Marcus GriffinTypically as part of a modification the bank will have a “shock package” which includes information and forms to be completed by the borrowerOn those forms there are questions like will they or do they occupy the property, there income, do they plan on keeping th home.This is equivalent to lying on a bank application which is most likely considered fraud Not providing legal advice but this is definitely a very slippery slope you are getting involved in.

But, this might not exist prior to close.Although I'm just starting out and don't know too much, I would think having your tenants sign estoppel certs during escrow (as @Aaron K. suggested, to which I just learned) is necessary so as to avoid any unwarranted legal disputes. 

Is it better to respond legally or simply to fill out the form. 

If you need financial help, ask under the "Finance, Tax, and Legal" forum.

I'm considering buying a property in Southern Maine that is about 5,000 sq ft too small to legally subdivide per the town's zoning rules.