Can you be 16 to choose which parent you want to live with?

I think you should get your mom to hire an attorney to get this accomplished in family court.

I'm annulled and gaining sole custody over my 6 yr old son and applying for k1 visa, i still ask permission from my ex husband?

This is an immigration question and not a family law question.

Is 6 days enough time for a child custody trial ?

Probably but you need to discuss this with your trial lawyer. If you have none you need one badly and immediately,

Should I get a family attorney? What rights do I have as custodial parent?

Go in for an in person consultation with a family law attorney. Grandparent rights are different in every state. In some states like Illinois...

Can my son take his daughter from one state to another , without moms permisson if they breakup?

I agree with both previous answers by the learned colleagues. That is why you should make sure he goes in person for a consultation before doing...

A few days but the steps getting to that point can take a year or more.

I don't qualify for legal aid and nor do I have $3-5,000 for a lawyer up front. I have to go to juvenile court without one.

If you do not qualify for a lawyer then you must hire one. You can call around for one that accepts payments or borrow funds or get an advance on...

The custodial parent is probably not going to have a basis to stop this vacation.

Should a 13.1 form be filled out by the legal guardian prior to a child representative rendering/accepting services?

No the court appointed the lawyer and it is entirely up to the court if the lawyer gets paid. If you have income the GAL should be paid.

Is it legal for a 28-year-old to get a 17 year old ..parents are ok with it

17 is the age of consent in Illinois. There is nothing illegal here but the parents might not be happy about the age difference.