My class is like that, too, SC.
I run a Responsive Classroom and even though I know it's working, it's not easy like it has been in the past. I have some of the worst offenders this year in terms of interrupting, breaking rules, not even understanding the rules half the time, and one of my kids this year, a girl, is neaky, sneaky, sneaky!! I catch her most of the time - and I say most of the time because I am sure she has done things I have not caught - but yes, it's HARD. There are days I have thrown RC language aside, and rather than saying to a royal pain in the butt who never does what s/he is supposed to do, "Remind where you need to be," or "Remind me what you need to be doing," I cut right to the chase and say firmly,"You need to be __________, right now, you may not get up out of your set again for any reason other than a major emergency!" and if they do, it's a reminder (card flipped on a chart).
I can't do a lot of choice academics this year because my class cannot handle it. I have completely given up centers anyways - I am all about Reading and Writing Workshop now - there are choices there but not like when I did literacy centers - so that makes life easier for sure!
We are going to start Book Contracts after the new year - we will see how that goes!!