so if you defeat the trickster,,,and you have an opponent in the same region as you,,,can you take the bag of carrying?? and another question,,if this person is in the same space as you,,,are you able to take all the items from the space if he drops the 4 items that are in the bag of carrying??

You can take Bag of Carrying/Holding or Concealed Pouch after defeating the Trickster. IIRC, one of those if you lose it, you lose everything inside, so could lose quite a few Objects if an opponent beats the Trickster and takes the Bag. As for the ditched Objects, no, not until you move away and land back in the space they are in.