Most people have said that his jutsus were stored in his sharingan, not full memorized. If that was the case than he lost a huge amount of power. But he is still far from weak. He is a brilliant strategist and an awesome guy.
Hiruzen, Itachi, or Hashirama would make great teachers. The best would have to be Hagoromo. Few people are ready for his teaching though (clearly as the world continued to progress further into war and abuse his Ninshuu teachings).
I make tonkotsu all the time. It's great. I don't really eat meat, but I like the pork flavoring. Instant ramen is garbage once you have real ramen. Vietmese and Hawaiian noodle soup is good too. You gotta try them!
I feel like Kishi just trolled everyone. I was listening to some epic Shippuden OST too. I literally facepalmed. It is a very Naruto thing to do, but good-grief.