If Durant is a no-go, then I'd say the best case-scenario could still be pretty good.
BCS Trading the Pick for a Star - If we could trade for Cousins and still sign Horford to play PF next to him, which he's pretty hell-bent on apparently, that's still the favorite for the Eastern Conference, in my opinion, especially because that frontcourt would present some heavy matchup challenges for Cleveland.
If we couldn't sign Horford but still could trade for Cousins, then I wouldn't mind giving Deng the "Amir treatment" and overpaying him for 1 + 1 type of deal to play the small-ball 4 for us. That's still a really good two-way team with IT, Bradley, Crowder, Deng, and Cousins.
BCS Keeping the Pick (Picks 1-2) - If we decide to keep the pick and make no big trades with it, then I see us rolling out with a very similar squad next year with either Ingram or Simmons starting for us. Maybe we try to package our later picks and pick up someone like Poeltl in the middle to later parts of the lottery. Unfortunately, I could also see us reaching and paying big money to a Barnes type or even a Beal type of player.
BCS Trading the Pick for a Non-Star (Pick 3 On) - If we get pick 3, 4, or 5, I think a trade for an Okafor, Noel, Favors, etc. would be the best case scenario for us.