Crash has to be the first forward off the bench, play something like 28 mpg and get easy transition points and rebounds, play good D and feel like a 6th man. That would maximize his value to a contender/fringe contender. He's not a good option as a starter at this point, so there's that.
Philly is under the salary floor, right? Humphries was DNP-CD for a lot of games last season, so they can use him that way if they're afraid it will hurt their tanking season. Danny has to send him for a TPE and a 2nd rounder. Humphries contract will be more valuable at the trade deadline, where the Sixers could get something better than the 2nd rounder. Win-win. Do it Danny.
Bass is a good player, but he could help the Pacers or even the Wolves who are trying to build something around Love/Pek/Rubio. Send Bass to the Pacers for Mahinmi+future 2nd or to Minnesota for Derrick Williams. Either way, the Celtics save 2M/year, and get another trade chip.
Start Sully/Kelly and give minutes off the bench to Crash and the youngsters. Maybe at the trade deadline or around the 2014 Draft, Crash will have some value and help you to get an All Star big (Marc Gasol/Aldridge).