In Maratis, interactivity is built around 3 tools :

- Behaviors : apply predefined behaviors to objects (like follow, look-at or custom behaviors)
- Lua Script : to script the scene events (collisions, keyboard events, timers...)
- C++ plugins : to write specific game code, write custom behaviors and custom script functions.

The behaviors are set visually in the editor, it's the most simple part, but there is not a lot of behaviors by default yet.
You can also attach objects in Maratis using the "Edit>link selection" menu.

For scripting, you can look at the functions list here, the script loop is synchronized at 60 frame/sec :
http://www.maratis3d.org/?p=269

You can look at the tutorials and docs here :
http://www.maratis3d.org/?page_id=53

There is a general video here :
http://www.maratis3d.org/?p=477

About your mesh follow and look-at question,
it's simply using a behavior with the name of the target to follow or look-at
(behaviors editing happen in the third tab when you have an object selected).

The feet-box is just a trick to be sure that the object touch the ground and not the walls
(because the box is a bit smaller than the collision box).

Multiple camera is possible, start by setting all your cameras in Maratis,
then in script you can use : changeCurrentCamera(object)

I'd like to see your creation for sure, don't hesitate to share some screen-shots and questions on the forum.

Looking at your examples it should be easy to make a character that's being followed and looked at like in Maratis Demos and YoFrankie, but when I try it myself, it doesn't go as planned.

Why does the mesh follow the player object?
Where does the feet-box come in play? (I understand the collision-detection part)
Are multiple camera's and switching between them possible?
I'm probably missing some logic here, but that's what this forum is for, right?

If I get the hang of this engine and some real understanding of the logic behind and in it, I would love to help write easy to follow tutorials explaining the working of among other things your example files, so people like me can have a go at this..