im lookin at the first one
sounds pretty normal between siblings. maybe when they aren't bickering, get them in cooperative, non competetive activities together. have them help eachother out as much as they can stand. so i wouldnt say a punishment. if they wont stop arguing have them write down what they are feeling/thinking and show them to eachother so nobody gets talked over. and they both feel they're being listened to.
Forget making excuses and just try to quit smoking.It is possible and no more noisy smoke alarms to deal with.
