Read the instructions more closely ... the answer is contained ther.

Which is better when i apply a green card? before or after i change the address.

Wait until you change your address ... unless you have issues with the 90 day deadline.

They have their ways ... starting with having access to all airline passenger manifests.

Read the instructions on www.uscis.gov closely .. the site will tell you when to use the form.

If your prediction is correct ... on or after October 1st.

You should put BOTH addresses, with the appropriate dates.

Currently on F1 STEM OPT, laid off on 7.16.2020 and I129 got approved on 9.10.2020, can i still transfer the H1b post Oct 2020?

Did the company lawyer file the I-129 as a change of status? Talk to the lawyer AND your DSO.

USCIS didn’t receive my I-130

Send a copy of the I-130 along with a copy of the I-130 fee receipt and a cover letter.

Can i fix my partner papers if we get married at the at of 18?

Yes, if the 2 of you have seen each other personally in the same room in the last 2 years, you can sponsor him. You'll probably need financial...

Will someone go to jail for ACCIDENTALLY NOT FILING a tax return worth $23k ?

Not an immigration question. I've re-classified it.