Well, if this is a reason to award the Shaman a medal, then in my opinion, the one who starts changing the rules and balance after the game has already begun deserves it.
1) The set was in place for 2 weeks, and no one paid attention = everyone is to blame.
2) There was complete chaos in the order of actions initially. The points I raised were taken into account. No one else paid attention. See point 1). ;) By the way, the bard could have stopped all the characters you mentioned. But not with all the non-player characters.
3) Here, the question is about the effect of the block on doubled damage. One was blocked, the other was not. In the previous game, there was a similar situation with a troll and redirection. Here, the GM decides how the block/redirection works: on both damage types at once or only on the first. The only downside is that this should be written in the rules. But again, we didn't ask, and the GM overlooked it...
4) There are rules, and the GM didn't want to change them during the game. And that's exactly right!
Like Zadornov's story about the two ninth cars: "But the workers are also normal people and believe that the 9th car is the one after the 8th, not the one before the 10th." The Shaman doesn't belong to the "normal" ones - for him, a block that doesn't reach its target = successful