I mostly agree with this, but the Nika dream isn't any more vague than Ussop or Jinbei's dreams, so if she does inherit that from Kuma, it fits perfectly. The role is my biggest hangup. I agree she definitely needs one. That said, one can be introduced later like Jinbei. Off the top of my head, I think spy works well given her ability to disguise herself, to the point of even being able to infiltrate Mariejoic during the reverie without being discovered. This is probably the most impressive spy or reconnaisance feat in the series, far surpassing any of the cipher pols. It's not an established role, but it's an important job that she has incredible skill at. That could easily be her role.