Xiao baitu and other experts, address question, please help

Hi Xiao Baitu and other experts.
Look below about the address problem. make me think my case.

my address:
My family stays in address "A" and I am in address "B" due to job. Address "A" and "B" are different states. Address "B" is not stable, may change later. My most letter are send to address "A", like income Tax, bank statement, credit card bill, stc and address on my driving license is still address "A".

My 485 form: (EB2-RIR, from my spouse)
When I fill 485 form, I use address "A" because it will not change in near future and my family (spouse and kids) is there.

My question:
1. Should I fill AR-11 to change address?
2. If I should fill AR-11, will it cause 485 address change?
3. Is there a way to inform CIS my normal Address change but my 485 address does not change?

Thanks for help.