Unless you purchase an email plug in, you'll have a problem with this part: I then did a report layout for each student, in the form of a letter, containing information on his or her ranking, status, etc.
Emails from FileMaker are plain text so you can't email a "letter" as formatted on a FileMaker layout although you can save such a letter as a PDF and attach it to the email. You can put information from FileMaker in the body of the email and send it as a plain text email--so that's an approach you can probably get to work for you.
You might make sure that you can send one email to one student the way you want to first, then work on a script for sending it to all of them. Note that in the Send Mail script step, you can specify an attachment so it's possible to send out your emails to your individual students and attach the same assignment file to each of them. You can even send out a customized email to every record in a found set where each record stores a different student's email--so this doesn't necessarily require a loop either.