Elfangor

I've played Linden Realms before (which helped me figure out where the glowing tree was already), but for the gift I just went through the portal and ran right to the gift. You're not required to play to get the box, you just have to be in the area.

Meanwhile, the Great Giant Mouse

I just ran through there now and saw a box.

The HUD is part of the game. Do you mean you get a new one on top of each old one every time? Mine detached when I left.