Hi,
I'm also struggling with an issue but not sure if I'm right here 
I have a page (1) with many sub-pages (2,3..)
With (1) I have restricted access only for several user but for (3) I like to give access not only to see the page but also to edit the page - but the user should not have access to work on (1) or (2).
I hope it was clear what I like to have and yo ucan help me in this topic.
Additionally the user are from BCMW. That means they can already see the pages but cannot edit them.
thanks in advance!