Short answers, pulled from the story.
Sweden holds between 1,700 and 2,500 runestones depending on the definition used. The district of Uppland has the highest concentration, with up to 1,196 inscriptions in stone, while Södermanland is second with 391.
The Kjula Runestone, Sö 106, preserves a poem in the Old Norse metre fornyrðislag about a man called Spjót, meaning "Spear," who had been in the west, broken down and fought in townships, and knew all the journey's fortresses. Scholars including Sophus Bugge, Erik Brate, and Elias Wessén have debated how extensive his warfare was, and the name Spjót is unique in the runestone record.
The Þingalið was the personal guard of the Dano-English kings, an elite unit composed mostly of Scandinavian warriors that existed between 1016 and 1066. The Kolsta runestone U 668 in Uppland and the Råby Runestone in Södermanland both commemorate men who died in this unit's service.
More Anglo-Saxon pennies have been found in Sweden than in England because of the Danegelds, payments made by the English to Viking forces. The runestone Sö 260 at Södra Beteby was found alongside a hoard of several hundred English coins from this period.
Style RAK is considered the oldest runestone style. It is used for inscriptions whose runic text bands have straight ends without any attached serpent or beast heads.
Runestone Sö 164 at Spånga in Södermanland is the only known runestone with both text and iconography referring to a ship. Its ornamentation shows a vessel whose mast takes the form of a cross, and the inscription is attributed to a runemaster named Traen.