If the time for RFE to be submitted is 1st sept,by what time the company submit it?

Your question is not clear. If the USCIS gave you a due date of Sep 1st to respond to an RFE, you have to make sure your response is RECEIVED by...

My H1B transfer has been applied for by an employer.My question is can i travel to my home country with H1B transfer in progess?

I don't think it is a good idea to travel at this time.

Immigration Q.: I am extending my B-2 and my I-539 is ready to be filed with USCIS. I want to confirm filing address.

You package should go to Dallas, or Lewisville (if sent by express mail).

Immigration Q.: I am extending my B-2 and my I-539 is ready to be filed with USCIS. I want to confirm filing address.

You package should go to Dallas, or Lewisville (if sent by express mail).

Can I reopen my immigration case after it was closed?

You have to find out if your case is closed or it was denied. Please retain an experienced immigration attorney to help you.

I751 fee

You have to pay the fee. But you may apply for a fee waiver.

I-751 filing fee

You need to pay the filing fee again. But you may apply for a fee waiver.

Documentation for the form i485 andi130

I agree with my colleague. You better have an attorney to do it.

You should file G-639 to the USCIS. Here is...

What are the options if my company incorrectly applied for my H1B with previous designation?

Your company should file an amendment to the petition to correct it, because you can only do the jobs described in the H1b petition. The USCIS has...