His teachers will be very willing to submit the evaluations but they are not always really prompt about getting them done. I am concerned that this could impact his meeting the EA deadline. Is this correct that the whole application must be complete and submitted as a whole?
As Luigi said, the "Submit" button does need to be pressed before the instructor evaluations can be started. The evaluation forms are actually pretty easy/quick to complete, but the requested comments (letter of recommendation) can certainly be time consuming to draft. Your son can provide the following to his instructors if they would like to start drafting their comments before actually having access to the official evaluation form...
"Based on your area of expertise, please address how the applicant will perform in the following areas:
English Instructor
1.Perform in a rigorous curriculum infused with writing requirements
2.Demonstrate respect and compassion toward others.
Math Instructor
1.Perform in a rigorous technical curriculum
2.Demonstrate respect and compassion toward others
Coach or P.E. Instructor
1.Meet the rigorous physical demands of a military service academy
2.Demonstrate respect and compassion toward others
3.Compete in a NCAA Division III varsity sport."
In case you didn't know, it's not a great place for those who don't demonstrate respect and compassion towards others.