Is this paper 100% cotton rag?
No This will be a cellulose paper.
Hahnemühle will tend to specify if the paper is cotton in the description if it is not stated then it will be a cellulose paper
Is the anniversary edition of the Hahnemuhle watercolor paper hot pressed or cold pressed paper?
The Anniversary edition of the Hahnemuhle watercolor paper is Matt which means this is a NOT (Cold Pressed) surface for the supplier.
I hope this helps.