Blueb, try a soothing body lotion on baby after bathing, hopefully will make your baby sleep better. Also check if its too hot? Sometimes too hot, they will also be cranky cos sleepy but too hot to fall asleep.
As for nappy rash, why dun you try applying thick layer of desitin during every diaper change? It could help. Must change his diaper everytime he poo, otherwise will make his rash worse.
Whitegalz, wah...100 yr old grandma not everyone have leh...;p
Mrslim, your baby's urine so potent ah....can discolour the sling...