N-400 for citizenship

Yes, that is a good list. Meet with an attorney and he/she might suggest additional items.

Do medical emergencies apply for foreigners who previously overstayed in the US?

Yes, a US Consul can give her a humanitarian parole for the medical attention ... then she will need to leave again.

LPR petition for his F1 Mexican wife

The wait is about 2 years: http://www.travel.state.gov/visa/bulletin/bulletin_5733.html She can stay wherever she wants. But, if she comes to...

Does the child have to be under 21 when the petition is filed or when it is approved to count?

File FAST. If done before she is 21, she will be protected. Get an attorney to help and make sure you don't make a mistake.

Which are the necessary documents needed for submission and how much time it will take to get the approval of N-470

Like the other attorneys advised you, read the instructions for the form ... they list the recommended documents. The USCIS.gov website gives...

Selected as the best answer

How can show bonafied marriage with week paper trail

We need more information. If you two are not living together ... stop using e-mail and start using 'real' mail. Also, get affidavits from...

I agree with the other lawyers, write a letter & telephone. Of course, your best action would be to hire a lawyer.

I sent my i-539 to wrong address

Wait to see if they reject it. While you are waiting you should meet with an immigration attorney.

How do I get rid of someone else's name from FBI report?

I recommend, like the other attorneys, that you stick with your current attorney's advice.

I am filling out form I-864 Affidavit of support. I need help on Part 5 question 21...

Yes