The revision to the Star Wars movies come in three categories.

First, and most acceptable, are corrections of special effects shots and other technical type corrections. These enhance the film and are welcome if done correctly and unobtrusively.

Second are additions that Mr. Lucas thought would enhance or re-invigorate interest in the movies. These are innocent, yet annoying additions, such as the establishing shot for the entrance to Mos Eisley with the bucking Ronto and the silly Pit Droids.

The third type of revision is totally unacceptable, and that is additions that actually change the story. The prime example is changing it so that Greedo shoots at Han and Han only shoots back in self defense. Dumb. Han is an outlaw and it made sense that he killed Greedo. Now the story has been softened and sweetened unacceptably.

A long way around to answer your question. No changes of the magnitude you mention were made to Return of the Jedi. C3PO was always floated around by Luke using the force to fool the Ewoks into fearing him and obeying his command to release his friends.

The other thing you mention is confusing. If you are asking if there is a version of the movie in which Leia informs Luke that she is his twin sister, then no, that never happened in the original movie nor in any revised or special edition. Luke tells Leia, not the other way around. Her response when he tells her is that she knows and that she has somehow always known.

Hope this helps.

Daniel W Siddall