I too think that it might have been a different story altogether had Stefan not been compelled to forget about his encounter with Rebekah and Klaus. They really seemed to be into each other then. But at the moment, Stefan definitely loves Elena more. I really admired how he fought against the compulsion to protect Elena in 3.05. So, yes. Stefan loves Elena way more according to me.
I'm not really sure. I think he loved them in different ways. But I do think that if Stefan hadn't have been compelled and Rebekah not killed, I think they'd still be together.
