Can Klaus Be Daggered?

The only exception is Klaus that can't be affected by the dagger and Mikael who is daggered for less than a year, but he is entombed by Abby and daggered by Elena, making him neutralized longer than Elijah. The reason why Klaus never died from neutralizing his siblings is because of his werewolf lineage.

Does Klaus ever get Daggered?

Elijah and Klaus fought, and Klaus was stabbed with the dagger, successfully neutralizing him for the first time in history by a White Oak Ash Dagger. In City Beneath The Sea, when Klaus is still daggered.

Can Klaus Mikaelson be killed?

Klaus can be killed by the White Oak Stake just like the rest. That's the only thing that can kill him. The reason he said at the time he couldn't be killed was because the stake was gone, leaving presumably no weapon left to kill him. You cant rip off the heart or head of an original.