I'm no expert in Blender (or Carrara) but I don't think you can take bones into Carrara from another program, other that Daz or Poser. But, you don't need to use bones to open a door - just move the hot point to the pivot point on the door and use a constraint - I like custom, lots of options. The bone in Carrara will try and bend the door, unless you work with specific areas the bones will affect.

Never Give Up!