Top compartment or top bin is what most seem to call it. I would think a little goo gone would take care of that sticker for you.
For the cd changer, when I upgraded my head unit I decided to ditch the cd changer. I ended up buying a bin that fits in that same spot for sentras that didn't come with a stock changer. Perfect fit and looked stock.
As for the trunk piece I think I went through like 3 before I decided to do without. There was someone on here who made a custom wood cover with hinges that seemed like it worked well.