dude. it is obvious that Paolini has copied some bits from LOTR and Star Wars, but why should Paolini be singled out when u ur self said that Lucas and Tolkein had taken some stuff from other stories. It is not plagiarism because had ideas of his own. I mean come on HE CREATED HIS OWN LANGUAGE. SEVERAL TIMES. How would I know.... well my dad is a paralegal so I know this stuff.
Second what do u mean he had Plain Old Poor Writing. He had a huge range of vocabulary. Corpulent. lets see means Fat, stout or portly. so when he says "the skin around his face was dry and corpulent", he means his face was dry and fat. Another example: Prophecies means the foretelling or prediction of what is to come. so when he says "prophecies of revenge...rolled from his tongue", he means that the shade is predicting the future and the future in his case means revenge or death. etc etc.
So don't criticize this book if u do not have solid evidence that this is wrong. Look up the words before u make fun of it and also try and fit the meaning of the word to what it means in the sentence. There is an excellent website for this. Its called Dictionary.com. Use it!