Camera folowing floating object

I have 2 questions about the GE ( for now :stuck_out_tongue: )

1.) I have a robot modeled and rigged and in the game engine when he is still he is floating up and down. I added an empty in its “head” and parented the empty to the robot mesh. Next i parented the camera to that empty. Here is my problem : the camera is folowing the robot nicely but is also going up and down folowing the robots “floating movement”. How can i set the camera just to folow the robot and not moving up and down folowing his movement?

2.) the second isnt a exactly a question but i need someone to explain to me in few sentences how does the colision sistem work. I couldnt figure out the parameters with just playing with it:o . Or a link to a tutorial would be nice

I figured out how does collision work but i can need to play a bit with it more.But i get good colision when a cube touches another cue and that makes the scene restart, and i was happy but when i tried to apply actor and dynamic to my game model it starts spining like crazy and flies off the scene…i dont think that is normal. any way to resolve that?