Perm Applied and approved in 6th year H1b and I140 denied


I’m on H1b visa for 6 years. Including all recaptured time and my I-94 is expiring on 05/27/21. PERM filed on July’20(less than 365 days) and got approved on 27th Jan’21. My I-140 premium denied on 04/29/21 due to ability to pay. Now my employer is saying he will apply for New I-140 application in regular along with H1B extension in regular, So that I can continue to work. I am looking for urgent help on below queries.

  1. Does it legal to stay for me at this point of time by applying I140 and H1B extension along together before I94 expiry.
  2. I have the option to apply for F2 COS. So Now Can I apply for both H1B extension and F2 COS before I 94 expiry? I mean is it legal to apply for F2 COS with pending I140 & H1B?
  3. My child is on H4 now. So Can we apply for both H4 extension and F2 COS for him before I 94 expiry?

Many Thanks