How to understand that i filed form i 751 but receive stamp for pending i-90 in my passport after 2 years

That is a mistake which you need an INFOPASS appt to fix.

Can I work before filing a change of status - H4 to H1B

You cannot work until you actually have H-1 status. But something is very odd about your situation. I assume you work for a university or...

Can i show my new business as source of income in affidavit of support to sponsor my mom's green card?

Yes, profit from your business will count for your I-864

Yes, you should be able to renew although all DACA cases are within the discretion of ICE.

Can i know if my abusive ex husband is now citizen?

You really need to see a Board Certified immigration attorney. You must wait five years to apply for naturalization regardless of your husband's...

Immigrant visa IR1 sponsor new to job. How long before the sponsor can be qualified ?

You should be ok if she has 3-4 months of pay stubs. It would be better to find a cosponsor of course. I am concerned as to why this case is...

If i not reveal my minor child on my Permanent residence

That depends on why you left the child off off your previous case, but you will probably be ok. You need to see a Board Certified immigration...

Will I be drug tested?

Neither of you will be drug tested in the normal sense of that phrase. The Beneficiary will be tested for HIV and TB, among other medical issues.

Applying for both H1B and F1

If you get through the lottery you simply have two options and can choose either one. You have an attorney and should discuss this with him/her....

How soon after I get my EAD card I should begin working?

If the OPT is still valid and the job relates to your degree, you can use that until you get the new EAD via the AOS.