So, throughout the main story line, it seems that the character Esbern is Glitchy. First of all, I cannot hear Esbern's voice and the text disappears instantaneously. And at various points in the game, he holds back my progress in the of the main story line. For example, he is supposed to say something or do certain actions and he never does them and the main story doesn't progress. Any help with this?

His awesomeness warps time and space in his presence, thus causing text and speech caused by him to be incredibly fast.