Answer:
Things here are usually tagged with red stickers.
I am all around yet to me you are half blind. Sunlight makes me invisible and difficult to find.
I go through a door but never go in, and never come out. What am I?
You use a knife to slice my head but you weep beside me when I am dead
I can point in every direction but can't reach the destination by myself. What am I?
I am your mother's brother's only brother in law. Who am I?