Wow they noticed me!
Regarding 3.a.: It's most likely because of how damage by bullets seem to work as described in the rulebook.
If I remember correctly, it says that whenever a bullet occupies the opponent's space, they immediately go to the Blocking phase, skipping the Defense phase where one would play the Defense card.
That means that as long as the opponent has spirit points, they will always block bullets and spend 1 spirit, regardless if they had a card in play or not.
This is why there was so much blocking in my gameplay footage.