Valhalla
(paraphrased)
Did Odium Splinter all the Shards for the same reason?
Brandon Sanderson
(paraphrased)
No. Some Shards he Splintered because he feared the Shard itself, and some Shards he targeted because he feared the Vessel. He was working his way down his list in order of the Shards and Vessels he felt would be most dangerous to his plans until he got stuck on Roshar.
Valhalla
(paraphrased)
Other than Vessels, how many beings have lived from before the Shattering until the time of The Way of Kings?
Brandon Sanderson
(paraphrased)
More than you would think. Longevity is not hard to come by in the cosmere. That much longevity would be a little uncommon. But certain species are particularly long lived, and certain magic systems enable longevity.