Green card through international adoption is complex and the USCIS will scrutinize it. Your facts indicate that you probably will not qualify for...

Adjustment of Status!

I agree with my colleagues. You shouldn't worry.

To continue my business in long term what visa status or resident-ship I need to acquire?

E-2, if your country of citizenship qualifies.

Can I be pregnant and legalize my illegal parents? Or will my pregnancy affect the process in any way?

You don't need to be married to be able to sponsor your parents. However, you should be 21 years or older. Additionally, you may want to speak to...

Are there any specific visa categories applicable based on nature of business/Self employment

I agree with my colleagues, depending on your country of citizenship, you can apply for E-2 visa.

While sponsoring someone for green card does the sponser has to have tax return papers from last three years?

Only your most recent tax return will suffice. However, question 25 on I-864 asks you to disclose your income for the three most recent years.

Does everyone have to get biometrics taken for I751 petition?

Yes, I agree with my colleagues, biometric is required.

Change of status from L1 to H1

I agree with my colleagues, I-539 should have been filed on behalf of your wife at the same time you filed your I-129. Your wife should not travel...

OPT cap gap expired sept 30,2012 - H1B is in Pending status, Can I work after sept 30 ?

I agree with Mr. Kimura.

Will I come under CAP exempt or not if previous employer revokes H1B as current H1B transfer not yet approved?

Yes, I agree with the fellow counsel.