Choc, I know what you are saying in that W will take it as a personal affront if you get involved with the kids discipline but if it is affecting EVERYONE'S quality of life (the lack of order) then it is time for someone to take a stand. They will all thank you in the end.
I think they are never too old to be shown that their parent loves them enough to not allow them to behave like turds. Trashing perfectly good things and refusing to pick up after themselves is turd-ish but not the end of the world. I even read an article one time that cited a study that showed that children have prefer order to chaos, even if they are the ones creating the chaos, lol.
As NOPkins says, be the man of the hour and take a stand. Sure, everyone will fight you at first, but there will also come a begrudging acceptance, eventually.
I sympathize with your wife. It is a hard row to hoe, this SAHM gig, but you can help her be successful (or to increase her current success) and improve her self image by taking charge of the areas in which she may be weaker.
