I just double checked your questions. In general we do provide folders and the once existing idea of "context folders" has not been implemented. So the documentation was at this place not correct. It has been updated accordingly and the heading "Queries on inherited properties ..." has been removed. Sorry for the confusion.
Regarding your second question - yes, a folder needs to be created first before
you can actually reference it using the ID. It is not possible to do it in one go.
So I hope this answers all your questions.
Have a great weekend, Cheers Inga