If you are doing it as a passive investor, sure. Incorporating does not violate any immigration law. Working without authorization does.

It seems to me you may be able to get them to let you amend the DS-160 before the appointment.

Three years after you became a U.S. citizen, or five years after he immigrated, whichever is earlier.

There's no harm filing all three applications.

It would not be a violation of your status, since you are already in violation of status. There may be private schools that do not require proof...

If she did not overstay then she should not have been removed as an overstay. Get a lawyer to try to have the removal order reversed.

Form I-129F is a fiance petition. It is not an application for the child of a U.S. citizen or permanent resident.

What category is it? F2A? if so, your child is under the Child Status Protection Act and you don't need to do anything in particular but pay the...

Check the CIS website for processing times. Yours is probably normal.

You can call customer service and ask them if you are required to do that.