How to find if I have a 10 year bar on me because of illegal overstay more than 1 year in US?

If you overstayed I-94 for over a year you are barred for 10 years. You will be informed when you apply for a visa at the Consulate abroad.

Can I apply for a change in status from H1B to F1 three weeks before starting school?

Even if you apply, it will unlikely be approved in 2-3 weeks.

Can i withdraw petition filled for a husband after two years of marriage

You can always seek to withdraw. However it depends on the USCIS whether your wishes will be granted and how they wish to proceed regarding the...

I filed an I-130 and it was approved for my husband.

For GC you will need an eligible sponsor.

Hello, I am a dentist from India. My wife is a US citizen. Our CR1 case is at NVC almost last stage. Waiting for my Interview.

I am not sure I can figure out where you are physically. If you are in the U.S., you may want to apply for adjustment.

Can a denied applicant apply for immigration again?

It depends who the USCIS considers to have misrepresented. Is the daughter a minor? If yes, she stands a good chance to have a new application...

What application are you talking about?

So your uncle filed the I-134 to support your stay? You cannot cancel it.

B-2 VISA extension applied and left USA before I-94 expired

A. no adverse consequence B. if you leave before I-94 expires, no consequence C. see above

Can it hurt me?

As long as you filed and paid taxes owed, you should be fine.