Does the pen has an eraser, say at the other tip of the pen? And, how to switch between pen-input vs highlighter?

Does the pen has an eraser, say at the other tip of the pen? And, how to switch between pen-input vs highlighter?

Yes, here is an eraser at the other tip of the pen for Max 2. When you are in handwriting mode you can just use the other tip as eraser. The Pen-input works only in handwriting mode, including sidenote mode, full screen mode and scribble. When you are in handwriting mode and you want to use highlighter. You should exit the handwriting mode at first. Then you can use highlighter. So I think here is no shortcut to switch between pen-input vs highlighter.