How can I enable the mouse in BaseGame like normally with SimpleGame, so I can look around? thx :?

take a look at BaseSimpleGame to see how things are set up

I don't understand how to use the MouseLookHandler. Do you have an example for that? 

MouseLookHandler  is a input handler, so you need to update it.

   MouseLookHandler mouseHandler = new MouseLookHandler(cam, 1);
   protected void simpleUpdate() {