A quick informal risk analysis suggests that level of technical security is unnecessary. The content of the message is going to be a lot more identifying than the address and account, because it's going to discuss details only a few people have access to. At the same time, the attackers (schools/employers) have limited options: they can't use the law and they probably don't have a lot of experience or will to investigate leaks.
I'd suggest using a throwaway (with nothing linking it to your other identities, of course) opened and used from a public network somewhere you don't usually go and where you can't easily be identified (i.e. don't be the only person in that Starbucks). Where possible, remove any details from your report that don't directly pertain to the problem. Oh, and don't post about your plans or the problem from an account with tons of identifying details.