Yay for Noah Bennett as Caroline's vampire-hunting gay dad!
They did some cart-before-the-horse writing here. I've been wondering why it's so all-fired important that Klaus not know Elena is alive. He got what he wanted, why should he care if she's still alive? But now we know he didn't get what he wanted (although the logic is sketchy; if the doppleganger died, then why should it matter if she was resuscitated? was there a footnote that Klaus failed to read?)
But the reason for the angst is that the writers would know it would become important that Elena's survival stay secret. Funny thing is, the gang doesn't even yet know why it's important. I guess they've been reading ahead in the script.
I agree with the general disapproval of Klaus, but I'm not sure if it's just the writing that's at fault. Klaus is just another Katherine, a character introduced in order to create problems for the gang to solve. This show doesn't invest too much in making those types of characters very compelling in their own right. They're just plot conveniences, not actual characters.
But the actor could do something to elevate the dull writing. Play the character as having some undercurrent - a desperate edge, or a gleefully malicious one - something really scene stealing is needed.