I believe you sent me a message saying you are looking at booking a seven day cruise. That is a good thing based on what you just said.
I just want you to know that I think everyone here agrees with you that we don't like seeing a lot of drunk kids on cruise ships.
To be honest with you, that seems like a different world to most of the posters here because that kind of behavior generally only happens on shorter cruises, like 3-day weekend cruises, which most of us rarely take.
Rarely will you see a lot of younger truly drunk people on a seven-day cruise. They attract older crowds and are much more family or couples-oriented.
Getting back to "common cruise ship courtesy" I agree with you that being polite with the crew and staff onboard is extremely important. These people sometimes have bad days, and they do work long and hard hours.