Can I apply for a new visa now?

You can certainly apply, however, due to the fact that you violated the terms of your prior visa, you may have trouble getting approved.

You will need to find a substitute sponsor or you case may be denied. You should consult an attorney regarding this situation. Sorry for your loss.

You should be able to open your own business in the USA with your EAD.

Change of status from j1 to B2 ?

Yes, can change to the B-2. You should contact an attorney to discuss the process.

How can my wife cancel my permanent resident card after it has been renewed ?

No, it's too late. She could have withdrawn the application before it was complete or conditionally approved but not after it's been renewed.

HOw can i made a second affidavit for my nvc case ?

If you find a joint sponsor, they would need to fill out an additional I-864 form. Can't comment further without more information.

How much would an attorney charge to prepare a R-1 Visa here in New York?

I would contact several attorneys and find one with whom you feel comfortable. We aren't permitted to negotiate with clients on Avvo Q&A. You can...

If my parent petitions to bring me to live in the USA as a green card holder, will the petition affect my 10 year tourist visa?

it depends on the situation. If your parents petition for you, it will be years before you are eligible to get your green card as an adult child.

How likely is it that people will not be able to petition for parents or siblings to live in the USA as green card holders?

Green card holders cannot petition for extended family, just immediate family.

Should I get a new visa stamp?

Talk to your new school's DSO for procedures required to maintain your visa status.