You may seek another advisory letter and respond to the letter received.

How can I proceed to reopen my OPT-EAD application which was denied for my situation detailed here.

We had a similar OPT EAD approved at the discretion of the officer.

I have two sponsors for H1B, is there a necessity to inform both the companies about two petitions purely in terms of USCIS

The USCIS will treat each employer petition as separate and not communicate you have a second H1B petition filed.

Can I ask my older client letter (Not employer) saying that this is for future employment (Job offer) for H1 B application?

your employer may file an H1B petition for you to work at your past client.

Change of Address imiigration

It has been the basis for denial. But, even a late filing will prevent a basis for denial.

Perm and h1b related

OPT experience with a different employer might be considered. It may be considered for knowledge. A denied I-140 will not render the H out of status.

Does AOS interview needs my wife to accompany me? (AOS based on Diversity Visa)

A DV AOS does not require the general checklist documents of wife or marriage. You do need documentation to demonstrate you qualify for DV AOS...

Apply for the SSN with EAD ?

yes, she may apply for a SSN with the EAD and passport and/or birth certificate.

How can i obtain F1 visa without leaving to my home country?

It is possible, but unlikely a US consulate or embassy in a third country would entertain your F-1 visa application.

Is it possible to do AoS for parents with a NTA in 2019?

If you are a US citizen you should begin the process for your parents immediately. You would then seek the government to cancel the NTA.