Bingowings said:
It would be better with an episode six made with as much care and attention as 4 and 5.
The problem with ROTJ is that it's all tying up and no story.
Kill off Jabba, Kill off Fett, Kill off Yoda, take Luke out of love triangle, kill off Piett and the Executor, Kill off Palpatine, Kill off Vader, Kill off the whole Empire.
That's the film, a shopping list.
Kill off Owen and Beru, kill off Greedo, kill off Alderaan, kill off Obi-wan, kill off Tarkin and the Death Star.
I would disagree that the Empire is destroyed, despite what the SE trilogy depicts. Crippled? Perhaps.
So by my count, six major players are destroyed in episode 4, if you count either the Death Star or Alderaan. That makes them pretty much even on the kill count. The only difference is that we've had more time to get to know some of the characters in ROTJ, making their deaths mean more.
Many of the things you mentioned are in service to the story. Yoda died to put pressure on Luke, as he was the last trained Jedi. Jabba died to show that Luke was serious in his threats, and was indeed a force to be reckoned with. Either Luke or Han would have ended up out of the love triangle at the end anyway, and Vader gave his life in a heroic sacrifice to kill the Emperor and save his son. These deaths are all in service to the story. Could Yoda have been handled better? Sure. Did Boba Fett need to die in such an inglorious way? Of course not. I agree that it is the weakest of the OT, but to dismiss it as a shopping list is to do it a disservice.
There's nothing quite like death to heighten the stakes. If many characters weren't killed, Lucas would be blamed for trying to sell more action figures. Remember that Gary Kurtz, the man who left Lucasfilm because he thought that Lucas was selling out, thought from the beginning that Han Solo should die. Lucas said that people would buy more Han Solo action figures if he survived to have more adventures in EU land, so in that case, keeping a character alive was to the detriment of the original story.