Today I conducted two simple tests (Passed) :
New pupil : I opened Class 3 Portal course to enrollment right with date range : "02/02/07 to 02/03/07", a new pupil enrolled in Class 3 Portal after delivering Portal key. At the second, any courses (I mean meta-courses) his class has been subscribed (as descendent course), are at his fingertips.
This pupil tried to enter others Portal course, wich refused to let him in, since enrollment is closed (should it be opened, he should have given enrollment key).
New teacher : I experienced the same protocol with new user to be a new teacher : he enrolled in Teachers portal course after Admin has opened enrollment and his key delivering , and got access to any due meta-courses AS NON EDITING TEACHER, since I declared Teachers' Portal course defaut role to be so when I created the course. (and forgot to mention yesterday, and do not know how to access that parameter now that the course is created). Very useful !