Controller + Model vs Ultra-slim controller that barely does anything + Library

lol - it seems it was not much use.

You said you wanted to couple action logging with notifications. I would separate those out, they really do not have much to do with each other. That step alone makes the whole thing easier to approach.

Oh, sorry, I expressed myself in a really bad way there. By coupling (Wrong word, sorry for that =S) I actually meant that the Action System itself should work on it's own, while a Notification system will rely on the Action system: Every action will be logged with specific data (Blog example: If an user creates a blog, a blog creation will be logged with the corresponding UserID and blog post ID), and a notification ca be created with at its base an action (Blog example: The notification at its base contains a target user - the user the notification will be shown to - a message with placeholders, and the action ID the notification corresponds to. Then, the placeholders will be filled with the specific data from the "coupled" action.)