Do I need to submit any other documentation for my brother's children to be admitted to the US with him?

You have a long time before your brother can obtain his green card. Over a decade. You should read the instructions about dependents.

If i have a warrant for not showing up to my felony division court and i got immigration court!!

You need to hire an attorney as soon as possible. Failure to show up in immigration court will lead to an order of removal.

How long does the NVC take to get back to me

It could be easily another 2 months before you hear anything from the NVC. Be patient.

Is the cover letter obligatory while filling for n400 naturalization

Cover letters are helpful not obligatory. As long as you sent all the necessary documentation you should be okay.

Selected as the best answer

You will need to go to your home country in order to obtain a green card. Hopefully you have not been out of status for more than 180 days as that...

What do I do now that my I-130 is approved but I'm entering on an L1B?

Yes you should be able to file the I-485 for him. It may be better to wait a month before filing to make sure that you have all the paperwork...

Immigrant visa inadmissibility!

Yes there are regulations in place that the office must follow.

Immigration matter

Your I-94 should be online. You should contact customs and border patrol. Applying for asylum without an attorney is not a good idea.

Immigration

It is highly doubtful that any immigration reform will pass in the US at this is an election year.

Reforms

This is an election year in the US so it is unlikely that we will see a reform bill signed into law.