Having pre-surgery bloodwork done is the best thing you can do for your dog. It will tell the doc how all her organs are functioning. This way they will know what would be the safest anesthetic for her. Yes dog can eat hard kibble without a molar or two. In fact at the clinic I work at we sometimes have to remove all or almost all of some dogs teeth. They still can eat hard kibble (amazing). Yes she will be tired after surgery. Most vets send home pain meds and antibiotics. Healing time is fairly quick as the mouth tends to heal nicely. Hang in there you.