That was not being humble, that was "do you know who I am, I am going to be da King, bitch, not some measly Lord". D&D
If not clear, being satirical there. I completely agree with the ruination of the Jaime character. Maybe they had a point, that no matter how many good deeds an addict does after getting clean, it does not take much to go back to the addiction. Still, they were hamfisted in the way they did it. Jaime knew before hearing about Dany's dragon that Cersei, if she lost, likely was going to be worm food. Then that revelation should not have caused him to go 180 on all the character growth he went through over the better part of a decade.
The whole Azor Ahai thing and the three heads of the dragon I can see them claiming that Dany, Jon and Drogon were those three heads. Jon had to put a blade in the heart of his love, Dany, to bring about the flaming sword(Drogon melting the Iron Throne, made of swords, setting them alight). It could have done with a little explanation though, maybe from useless Brano.