Mini, Everyone knows about Come Together. Sure, John used the line "Here Come Ol' Flat Top" from Chuck Berry, and was sued. I agree that was stealing. But, He didn't steal Because.
Quote from Wikipedia:
"Legend has it that this song is actually "Moonlight Sonata" by Ludwig van Beethoven played backwards. While this is not precisely true, "Moonlight Sonata" certainly served as an inspiration for the song. "I was lying on the sofa in our house," said Lennon, "listening to Yoko play Beethoven's 'Moonlight Sonata' on the piano. Suddenly, I said, 'Can you play those chords backward?' She did, and I wrote 'Because' around them. The song sounds like 'Moonlight Sonata,' too." "
In no way did he steal anything, how can you say he did? Heck, if using chords from another piece music is stealing, then anyone that ever wrote a song is a thief!
And Paul didn't steal Golden Slumbers or "nick it" like you claim either. Golden Slumbers is a traditional lullaby. One day while Paul was visiting his father at his Cheshire home, he began playing the piano, and looked through a songbook that belonged to his stepsister, Ruth. In this book he came across a traditional lullaby by Thomas Dekker from the 17th century. But, as he was unable to read music, he began to make up his own melody and new lyrics, and Golden Slumbers was born. Golden Slumbers is traditional and public domain. There is no harm in taking a traditional song and arranging it differently. Anyone can interpret a public domain song any way they want.
Now, can you kindly explain what you mean about Oh! Darling?