steroline is not the back up ship, honestly, stelena was the back up to delena after all was said and done. lol and caroline never liked klaus in that way, at least not early on because he was such a bad guy. they built S/C up for 4/5 seasons, more than half of the series and they were the main ship focused on in the last 3 seasons.

i could name so many things that klaus did horrible wrong with caroline lol. no one is perfect.

He definitely doesn't love Elena more than Caroline. He loved elena for at most, 2 years time. in all the time that he was dating/in love with caroline it equaled to around 5 years. So much more than Elena, not to mention the trust and understanding they built up in the seasons prior to when they got together.

But again, different strokes for different folks! i got my endgames so the writers obviously agree lol.