New Update:
I am able to fix the session list not showing up, and I am able to implement the functionality of Disabling New Enrollment XX days before a session starts. (though the code might be messy and not up to standards )
Now the only thing remaining is Disabling Auto Enrollment XX days before a session starts. (to be more clear, the person in the waiting list will be still in waiting list if xx or 'less' days are remaining for the session to start.)
Like I mentioned, I am new to moodle and facetoface, so my approach until now is just trial and error, so if anyone knows where the logic for auto enrolling is implemented, please let me know... (I'm guessing its in ./lib.php)