This is a big mystery to me. When Qui-gon is killed, his body doesn't vanish like Obi-wan or Yoda, when they die. Even Anakin, after spending half his life being an evil henchman for Darth Sidious, supposedly vanish from his suit. (Luke apparently, burns his suit on a funeral pyre as a symbolic act).
Why doesn't the man, who is the one that learned the technique and was able to pass it on to Obi-wan and Yoda, appear as a force ghost? I've heard that the technique is based on love or something, and Anakins love for his son allowed him to transform into a force ghost after his death. Qui-gon loved all living things. I know that you hear his voice when Anakin slaughters Sandpeople, and he appears in a dream Yoda has in the Clone Wars cartoon, but that's not taking a physically visible form, did he simply not choose to (didn't Liam Neeson want to make a cameo appearance)?

Also, should we refer to Palpatine as Palpatine? After all, wasn't that name just an alias for Darth Sidious?

MTFBWY!