Can I travel within US with expired I 94?
Yes you should be able to travel domestically with your valid passport as I94 are generally not inspected when traveling.
Can I fly domestically with an expired visa?
Fly domestically in US with an expired visa but your I94 is still valid is ok. You may enter US on the last day of validity of your Visa and still stay up to 6 months after.
Can I travel within the US with an expired foreign passport?
An expired passport is simply not acceptable for international travel. You’re not required to have a passport to board a domestic flight – at least not yet. However, you do need valid identification to get past the TSA checkpoints. By definition, an expired passport isn’t valid.
What if my visa expires while in the US?
When your US visa expires has absolutely nothing to do with how long you can stay in the US. US visas are solely for entry, and the visa’s expiration date is simply the last day on which you can use that visa to enter the US. So yes, you can legally stay in the US after your visa expires, if you are in status.