If he's from Germany, calling someone by her first name would be natural.
Ninja martial arts... It's like 97% bullshit and modern interpretations. Mostly because things hat are secret tends to not get passed down, and ninjas were not warriors other than coincidentally.
Of course she's happy. She got a compliment. Otherwise she wouldn't be so embarrassed.
Watching someone who's watching others shoot arrows. It's a bit creepy.
This is what we call "a cliffhanger".