Note: This question is in fact hypothetical--but any suggestions for edits that could make it a less ostensibly CYLOR-type question would be welcome.
Let's say I attend a university which requires all incoming students to sign an honor code which states that they will report any incidents of cheating/unethical behavior that they observe other students committing.
1) Would reporting these incidents be a violation of halacha* if I told on a Jewish student?
2) If yes to #1: May I sign this honor code, with the knowledge that following through with the code could in some cases be a violation of halacha?
3) If I do sign, and then I do, ch"v, observe a Jewish student cheating, what must I do? Would there be any possible halachic leniencies to report the cheating?
4) Would any of the above change in consideration of the fact that I myself may be punished (i.e., expelled) for not reporting the cheating?
*The potential issues I have in mind are loshon hara and mesira. In light of the latter possibility, it might be appropriate to consider two (three?) separate cases here: one in which one is reporting to academic authorities who are Jews in a Jewish academic institution (such as YU or possibly an actual kollel/yeshiva); one in which one is reporting to academic authorities who are goyim in a secular institution; and (maybe) one in which one is reporting to Jewish authorities, or a mix of Jewish authorities and goyim, in a secular institution.