About Alen raising his voice, I think it may have been entirely justified. I get the feeling he may have tried to teach someone else to use magic only to have disastrous results, leading to his apprehension towards teaching Reamus and how overly emotional he seems to get during the whole scene.
As for the abstract monologues, they seemed fitting in my opinion. People don't always have coherent thought processes, and with how Reamus seems to get lost in thought fairly often, his mind is likely to wander.