We've never had any issues from staff regarding Impero being on their computers, but that may be because it's been here for years and is just accepted. Provided your AUP specifies that their activity will be logged I don't think you really need to consult them, but if you need to then push the remote support - "we can help you much more easily and quickly" etc. We don't give staff access to the console, it's just for us admins, but if you're going to then classroom management can be another plus. As for logging, each school will have different needs, but I'd suggest too much info is better than not enough - provided you're just logging violations and not blocking. If the logs start to become unmanageable then review your key words and ease things back.