Waiting for Adjustment of status. Can I already work with old Social security number DHS?

No you are not allowed to work without an employment authorization card under the facts you presented.

Facts are too complicated to answer in an online forum but your case should be doable.

Does the USCIS know have records of child even if he or she wasn't on the forms?

You definitely want to mention the child in the interview and bring a corrected page of the application with the child's information

H-1B extension with new employer with approved I-140 from previous employer?

Absolutely this is allowed -- just make sure the attorney knows to include that old I-140 approval.

Can I continue to own a property in US, though i am leaving US for some time as I don't have a valid status to be in US?

yes that is legal to do while you return home

good chance she can enter on her B-1 with no problems. If she mentions she is coming to help you take care of your child though that is...

Send a letter to the asylum office by courier and keep a copy with proof of receipt and advise you wish to withdraw. Show this to the Officer at...

Is the EB2-ROW visa numbers already retrogressed in August ?

They retrogressed before September and will likely be current in October 2018 -- the Officer is correct.

Can I ask to change to different name because I do not want the name I filled out on the application N-400?

yes that is doable; request the exact name you want at the time of the interview.

check with the Service you want to join and see if they will assist with your citizenship in exchange for your commitment of service to them.