Well, I'm not new to Construct, and it's my fault for assuming everyone would understand what I'm talking about.
What I mean by a "RPG Maker like event system" is a common feature in top down RPGs.
You can set multiple "events" that are represented by a box on your map. Each box contains some piece of code that can be run using a defined trigger: Automatic, parrallel process, Action Button, and collision.
For the moment, this is quite easy to set up on construct. What is harder tho, is how that piece of code is processed.
In RPG maker, you associate a list of actions to each event, and those actions are realised one at a time. Some are realized together, some need to pause the event processing and so on.
For exemple, if I need to make a cutscene containing two NPCs walking along and talking, all I'd have to do would be to set a move route to each NPC, have it loop (or, not, depending on what's wanted) and then add the "message" action and set the actual message as a parameter. This message actions are listed one after another, and the next message action is not processed if the previous one has not been ended (aka the enter have been pressed to terminate the current dialogue). However, the message actions do not prevent the NPCs from walking. So you have to set it so some action can restrain other actions from happening but not all of them.
I have a very blurry idea of how to do this using a 3D dictionnary, a list or an array. But it's very sketchy, and I'm not sure how to do it in a way so it's extensible.