"But the book doesn’t seem interested in this, they dismiss everything he says as lies even though we’ve seen otherwise ourselves."

Because everything he says IS lies. I don't know how you can misunderstand this.

"That’s especially bad since Jamie and Å were knowingly keeping Morgan le Fay hostage in conscious stasis and friggin’ vivisecting her for a mix of cruel experiments and general entertainment, and at least one of our heroes knew."

Jamie and A are bad guys. That's just who they are. That doesn't mean removing Morgan le Fey from power was the wrong thing, it was just Evil vs Evil. Jamie and A, however, have shown that their evil is in service of a better ideal -- making sure mutants are safe -- while Morgan le Fey's evil is, you know, just generically evil.

"You do know Scotland’s part of the U.K., right?"

That would make sense if his name was Captain UK, but it's not. That's a completely different character.

"The only help this Excalibur has done has usually been entirely out of Krakoa’s or Å’s nationalist interests."

That's also completely untrue. They have helped plenty of people in both Krakoa and in Otherworld without those ulterior motives.

But apparently it only counts if they help British people. Which is just silly.