Dear Maruška,
thank you for a really nice comment :) I like your suggestions and will add them to my observation sheet.
When I was looking for the information about error connection, I found that the T should correct students' errors nicely and move on quickly and not make a big "thing" out of it.
I would love to use music in my lessons! I think that music can do so much good and calm children so they feel relaxed and not tense.
I wish a nice evening to you, too, Maruška :)