CaptainS, I think what you are trying to achieve here is admirable, however, I would suggest that you go about it differently.
The survey monkey suggestion is a good one, with specific questions aimed at identifying specific problens rather than whether or not cadets felt that they were treated badly or not.
Physical abuse is clear. Verbal abuse should be clear, but in some peoples' eyes being told to get their arse out of bed in the mornings after being late for watch is verbal abuse.
Lack of interest is also ambiguous, I was once told by a cadet that he was there to learn, not to clean, it would have gone down better if I did not have a mop in my hand at the time as it was a ship with no engine room ratings and we all did our bit cleaning.