Will my bad credit history prevent me from obtaining a H1B visa.

I agree with my colleagues. Generally credit issues are not a reason for denial. Contact a US immigration attorney for review.

Can they file for an extension? They just want to finish their treatment.......

If they are here in B2 status, then an extension can be filed with USCIS prior to their current expiration date. Contact a US immigration attorney...

How can she stay here without a sponsor

I agree with my colleague. Contact a US immigration attorney for a review of her situation.

Can I get a new J1 visa it hour completing the HRR under my old J1 visa?

Technically a new visa can be issued, you will still have to fulfill the 212e requirement prior to filing for any H1B or green card application in...

Does it make sense to change the address now to the KSA address to try to expedite the interview? (KSA faster than Egypt)

Changing the Embassy will delay the case further. Contact a US immigration attorney to review your case and determine whether you are in standard...

What the chance of reinstatement after this long period?

I agree with my colleagues. There is no way to predict the chances of approval. Contact your DSO for assistance.

Start University Classes while H1B to F1 COS is pending

I agree with my colleagues. Contact your DSO and/or US immigration attorney for strategy assistance.

If my H1 to H4 is approved next month and EAD is approved 3 months thereafter, can I continue to work in H1 for the 3 month gap?

I agree with my colleagues. Contact your company's US immigration attorney for assistance.

I agree with my colleagues. List "self-employed" for those periods. Contact a US immigration attorney for assistance.

Can my wife enter US while my petition is still under processing? What documents she have to carry at POE?

I agree with my colleagues. Contact the company's US immigration attorney for assistance with the H4 packet.