Shareware education

I try kami but i think integration is not so clear because i can’t know if my correction is keeped in the classroom interface that i want to give to my students.
Could you give an indication that confirm the work is saved on the interface ?
If we can download our work is it because the work is not integrated in the google interface ? May you show options to choose to deliver the work with or without annotations ?
Why rotation is not directly possible in your tool bar ?
What will be the copy student at the end : a kami copy in different interface or a google integration in place of the original work ?

May we can try premium features to know if it is really essential ?

Thanks
Sorry for my english im french