I'm aware that there was a lot planned before Sladen's death such as Mr Smith taking human form, the Trickster returning for the Season 5 finale and Tom Baker returning. If Sladen was still alive what would you have liked to have seen?

If he was willing to do so I would have liked to have seen Sean Pertwee play the 3rd Doctor in an episode where he reunites with Sarah Jane, Jo Grant and maybe Captain Yates and Sgt Benton. Since I heard they considered making a version of a Christmas Carol with Tom Baker, I'd expand on that idea by bringing back some of the other actors who played the Doctor. If Sladen chose to retire, for the show's finale I'd have Luke take Sarah's place as Earth's protector.