I agree with Jay and his idea to use the card practice system for individual behaviors.
AS far as the scoreboard goes, I use it to reinforce specific behaviors that I am looking for....but mainly following directions quickly and participation. Whenever I give the frowny face (when I don't have everybody) I have them practice, practice, rehearse, rehearse with me couple of times. With this, I ping pong them back and forth on the scoreboard (for instance maybe I start out with a frowny, then a frowny, then a smiley, then a frowny, then a smiley---I ALWAYS try to end on a good note with a smiley....but note that it doesn't necessarily mean that we end up with more smileys than frownys) , which really gets them going and excited. Keep in mind what Jay said that YOU are in charge. You don't want to let them win everyday...you do want to keep them eating out of your hand. Also, I use the extra minute that they lose to practice whatever routine we are struggling with. The key to Whole Brain Teaching is to practice/ rehearse--not scold. If we are struggling in an area, I view this as an indicator that we need to practice.
Also, keep in mind that when I am ping ponging them back and forth on the scoreboard--our practices are short and quick--not over a minute--and our loss of time is gained in complete and total engagement. I don't know about you, but I wouldn't mind giving 5 min of time throughout the day to practice and rehearse to gain 5 hours and 55 minutes of complete and total engagement (and that would be an extreme case, anyway, because once you get them going it is unlikely that they will need practice-rehearsal time every day...in kinder we usually do, but when I taught third grade we could go for a couple of weeks before we needed a little refresher:).
Lastly, for your friend that is struggling with shouting out, it sounds like this student is already trying to self-correct, which is an indication that at least he is aware of the problem and is trying to fix it. Most students are quickly remedied when you say Rule #2, and the kids say "Raise your hand for permission to speak!" A couple of times of this and usually the student is toned down. However, if that doesn't work, and the individual card system doesn't work, I have a great Whole Brain Teaching strategy called "The Weekly Stars" which has helped me to practically eliminate shouting out in my class (we're not perfect everyday, but we're pretty stinkin' close

Let me know how all this works out for you, and if you need the secret of the stars I will gladly share with you:) !