Sounds like you and hubby have a plan, which is great. Aside from my own (adult now) kids, I've had a lot of exposure to young people. I am that there is such a fine line between "supporting" and "enabling".
, and I think that when there is other shit in the picture, as you have with these kids, the solution is that much more complex. If it were me, I would threaten a finger, rather than the whole arm, so that if push comes to shove, you don't shrink back and think..."Oh no...not the arm...how can they live without the arm"? No kid has yet died from having had their "toys" that is electronic goodies, removed from them for a set period of time, or until consistent getting together of shit has happened. Sometimes kids push, just to see what your cracking point in fact is. Certainly, I'm not suggesting that babies get tossed out along with the bathwater, but I'm sure that once you have a chance to catch your breath, and stand back to back with your husband and lay down and enforce your rules, you will all be much happier. Chin up, eyes straight and march on, I'm here with you. Ally.