What would b my status if i have an old felony and i been married to a citizen?

It depends quite a bit on the basis for the felony. Talk to an immigration attorney.

What is the chance of getting H-B1 visa for foreign trained dentist who received associate degree in dental hygiene in the USA?

Since the 'normal' amount of education for a hygenist license is 2 years, you probably won't qualify for an H-1B ... your prior education is...

Having H1B visa , plan to work from India few months? Is I am allowed?

Yes, you can do this. Have the company lawyer check to see what, if any taxes must be paid in India.

Will i be able to apply for some sort or visa to move with my boyfriend?

You probably have a 10 year ban and must wait another 4 years, or get a waiver. Talk to an attorney via Skype.

Can I apply for a visa extension (B2) while my H4 is being processed?

If a COS from B-2 to H-4 has been filed, there is no need to extend the B-2.

Filing for green card for husband and children?

Every one needs their own I-130. And, unfortunately, you can't file for the 22 year old.

Once the judge allows you to file form I-485 you can apply for an EAD. Once you have an EAD, you can get the other documents.

If my US citizen brother files a petition for I-130 visa then then can I travel to US from India during the pending status?

Yes, because this process takes more than 10 years, you can go back-and-forth.

Can a J1 holder, who accepted for residency, apply for a green card or an EAD?

Once your J is converted to a residency your DS-2019 will probably get annotated with the 2 year HRR.

It looks like you're a former diplomatic visa holder ... this is complicated and you need to work with an attorney. As for the medical, it is...