Ive never heard that Thor was on top before. I tentatively speculate that that assertion comes from someone more Greek myth oriented than I am currently. Zeus being the lightning/thunder god at the top there. Tiw is who I have known about to be the deposed king. See wikipedia's article here: http://en.wikipedia.org/wiki/Tyr It seems that his name is a sister word to latin "deus."
Viking Rune Stones are not particularly religious, but were basically grave markers for whoever's family had the money to have one made and cared to have one made. Most simply say "So and so commissioned this from so and so for so and so who died." Runes themselves hardly ever were used for anything more than writing the owners name on something or taking tally of goods, though magical uses did occur, particularly in repurposing of Roman coins http://www.google.com/search?q=bracteate&safe=off&client=safari&rls=en&tbm=isch&tbo=u&source=univ&sa=X&ei=yiL1U5i6Ko27ogTX_YDwAQ&ved=0CD4QsAQ&biw=1659&bih=936#q=runic+bracteate&rls=en&safe=off&tbm=isch. The runic system first was developed by the Norse, who adapted, most likely, Etruscan characters (possibly some Greek, too) into a form easily carved onto wood and sometimes stone. The Danes (a Norse branch) introduced this system to the English when they invaded and created the Danelaw, which was all of northern and central England, but not the south, where most of the Saxon and germanic-tribes-not-Angle-or-Saxon were. About one third of "England" remained illiterate until they rediscovered Roman characters in the 800s, well after the political/religious elite were literate in Latin due to christian conversions in the 5-700's CE. Runes took on immediate religious/superstitious importance for the Norse, but IMO not quite as much as modern Neo-pagans believe. IMO runes are nice, but they arent THAT nice. And, like writing in other parts of the world, it was restricted to the elites in society at the time.