Answer:
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
What is the saddest fruit?
The more you take away from me the bigger I shall get.
What kind of cheese is made backwards?
I roam through the lands hoping to rescue my love. I search high and low and will stomp on you if you get in my way!
I am rarely touched but often held. If you are smart you'll use me well. What am I?