nah nah
Outside of the knee....
Yes, it can as the vagus nerve relays the parasympathetic inhibition of the heart rate.
As long as it looks like it's healing.
No, they do neutral damage.
If you are talking about the numbness in and around your knee replacement, please do not worry as it is not a major problem or complication. Also if you are suffering from back pain following your knee replacement surgery and thinking it as a nerve damage doing some physical therapy will help you with that.
You always ice muscle, tendon, and ligament damage to prevent swelling and further potential damage. It used to be that after the first day or two after an injury, you would apply heat to bring healing blood circulation to the area. It has been found in the past couple of years that ice is somewhat better at bringing healing blood to the damaged area. Either heat or cold will be OK to apply after the first day or two after the injury.
It depends. If you want high damage, go with storm, if you want healing go to life. If you want healing spells that are mixed with damage spells choose death. I'd go with ice if you want high health. Myth is summoning minions to aid you in combat. Fire is like storm but is more accurate and causes a little less damage. Balance is, in my opinion, one of the best. It is full of buffs to make your wizard stronger, and is pretty much all the schools mixed into one. It is hard to master balance, though. Good luck!
Ice it as often as you can.
Lotsa ice
Fighting, Fire, Rock and Steel types are good against Ice
If it does freeze, no. The ice would damage the plates/circuitry maybe even the case.