Yes, it is illegal.
You win the round in wrestling and go to the house of the ninja and there he will give you the claws and more.
You get the claws after Basho reveals himself to you and teaches you to be ninja. (see related solution for how that happens)
you don't you just have to climb on the wood with the claws and then jump on it. (the claws are always on you if you are already a ninja.
When you do all of that stuff you earn the claws from Basho
yes.
yes
yes they are
Use the ninja claws to climb the tree.
You get them when you complete your Ninja Training. (see related question)
you have to beat the sumo reseller and then the ninja Master comes complete the training and you'll get them
You don't dock a puppys tail, it's illegal and cruel. And it's animal cruelty to remove its claws