Can an existing I-130 Immigration Petition impact petition for a new TN visa ?

TN requires non immigrant intent. However, you may still be able to get the visa. No one can guaranty anything.

Yes. You can do that. Direct this question to Canadian embassy though. They may ask why you were out of status and possibly deny your CA application.

It seems the company is very accommodating. Why don't you ask their attorney?

They are Can invite me for another interview ? If yes , it would be just me , or me and her together ?

You cannot get divorced and still remove the condition on your green card. This would consider as fraud.

Can I travel outside USA without H1B approval notice?

You cannot come back to US unless you obtain a new visa. You need to reapply for H1b from a consulate. Cap gap does not work in this situation. Why...

What happens if I get my EAD card (sent with AP and GC applications) after the H-1B denial 60 day grace period?

I agree with attorney Alexander. You need to consult with an attorney in private.

EB3 to EB2

That is possible but you need to sit down with an attorney who can provide you with best legal advice about your situation.

What i should do next

You will be instructed from NVC for whichever petition.

How can my minor sibling come with my parents to US when I petition them? She has developmental delay. And very dependent .

You can petition for them including your sister. However, working with an attorney in=s the key. Good luck.

Iwas wondering if I could start the application process towards legal residency or do I wait until my son is 21 to do so?

Your question is not clear. Are you the son or have a son who need to apply?