A:AnswerSprint is only rolling out network connectivity for any/all smartwatches in major cities only. Not even sure if Atlanta is deployed yet. Your best bet until Sprint's network supports smartwatch connectivity is to choose a non-LTE or Bluetooth only smartwatch.
A:AnswerOn My S4 I had scratches on the part that touched your wrist but I had that for 4 years. My s4 which I’ve had for a month now doesn’t. With the ceramic back it’s unlikely to scratch the back and as for the sides. It won’t scratch unless it takes serious damage.
A:AnswerYes, is measures you heart beats. A future upgrade, from Apple, will allow the user to actually get an EKG which can be shared with your physician.