I'm sure this has been asked or a forum started already in regards. But will all our toons transfer to the ps4 and the dlc and other items we've purchased her to the ps4?
Yes...I believe all of this is addressed in the Gotham section. One of the posts that SOE has commented in I believe. You will see the green SOE tag in front of the thread.
Everything will be transfered when you sign in the same PSN that you signed it with on your PS3. All you've got to do is DL the game again and then play it like you always do. of course, signing in with a different PSNH wouldnt get you the DLC's or Legendary Membership that you have since only the PSN account that has all of those features would be recognized as having them.