You really need to consult directly with a reputable immigration attorney to solve this one. Best wishes.

As we do not know the type of visa or petition since you did not mention it nor have we seen your documents, this question is nearly impossible to...

The educational institution must issue an I-20 for him to obtain F1 status. Work with the airline in question as to requirements for minors...

Yes if admitted to an educational program which is able to issue an I-20 for an international student.

Minors can generally fly unaccompanied with permission of parent/caregiver. Work with the airline in question as to what requirements they may have...

You cannot apply on his behalf for this. It would be the educational institution he is admitted to which issues an I-20.

Work with the school's DSO and your immigration attorney.

The F1 is duration of status, meaning it is generally good for the duration required to complete the educational program in which one enrolls on...

In any immigration-related matter, it is always best to at least consult with an immigration attorney to address your questions. At a paid...

It should be sufficient to cover his educational and living expenses. You can ask the educational institution for an estimate of what those might be.