[EricH]

I'm going to agree with the rest.

The rule is a team rule, and as such may be rescinded by the team in such fashion as the team chooses. FIRST does not interfere with team organization; in fact, the only requirement FIRST has for team makeup is that they have between one and three pre-college students (driver, human player, and operator).

I would advise your teacher to read the full manual, and the related documentation, found on the FIRST website. Much of this doesn't really change year-to-year, other than references to the game of the year.

Whether or not mentoring your old team during your first year out of high school is a good idea has been discussed before; I've seen it work and I've chosen not to try it myself. As you are local, stopping in to say hello and ask if help is needed from time to time should be OK, but your school should naturally take priority. Your best bet is to train some of the current students in your "field of expertise" before you leave.