Hi.
The ideas you have written yourself seem fine to me.
What age group do you teach?
I would suggest variation in the type of class, and in the way you teach, rather than trying to find a magic theme.
I live and teach in Japan, so I try to use ideas in which the kids already have an interest, and simply make it English rather than Japanese.
How about childrens � TV characters interacting with one another?
How about funny or weird pictures, about which they can make simple sentences?
How about characters and situations from stories that the kids already know, but in English?
I hope my comment is not useless. I have suggested doing whart I do, that is all.
Have a good day
:)