US Immigration from Bangladesh

My question is, Do EB1 gets priority before Eb2 or Eb3 or they are all in the same queue?

My mother (LPR) lives with me in the US as a dependent. She applied for my 3 younger brothers who have their interviews in a few weeks. I am the financial sponsor for their visas. The list of interview documents they should bring with them includes proof of domicile for our mother. I am not sure what proof to submit because she does not have any of the documents listed on this page: https://travel.state.gov/content/travel/en/us-visas/immigrate/the-immigrant-visa-process/step-1-submit-a-petition/i-864-affidavit-faqs.html#aos18

She has a state ID, social security card, medical bills, and I have claimed her as a dependent on my tax returns for the past 5 years. Will these suffice as proof of domicile? I wrote a letter explaining she is fully dependent on me as part of the initial paperwork she submitted. Should I write another letter for my brothers to take to their interview?

We were asked by the NVC to add a new household member to our F4 case. Soon after, we received the DQ email. Should we still add the new member's documents or wait for the US Embassy interview schedule? Any advice would be appreciated!

my mom's name on her passport is AZ. K and on me and sibling's it is AJ. U (shortened for privacy concerns). first name is the same, just different spellings. U. is my dad's surname, which was added to me and my sibling's documents by teachers in our school, without any permission from our parents. and when we found out about it later, it couldn't be changed.

now, my sibiling who is a legal permanent resident in the united states wants to apply for a b2 tourist visa for my mom. and later a ir5 visa when she becomes a citizen.

what issues could she possibly have applying for these visas for my mom? we tried legally changing her name but there was nothing we could do. its not possible so far. will my mom have any serious issues with applying for and getting her tourist and parent visa approved?

should we opt for a one and the same affidavit? will the us embassy accept it if she clearly explains it to them?

PS: I'M FROM A SOUTH ASIAN COUNTRY.

literally any help would be appreciated, thank you in advance.

So, we got this email back on January 19 asking us to add a new household member and upload all their documents. Now, we've just received another email on Feb 6 saying our case is in(DQ).

She is the spouse of one of the joint sponsors and we did add her, but totally spaced on filling out or submitting any documentation for them. Do we complete it further or remove her?