Vallen nice write up, though a few things you mentioned being from 2008 were actually from either 2011 or later at the earliest. For example Clarus was never shown in Versus at all, in fact he was only added to that scene of Regis vs Iedolas in the 2013 version of the CG, whereas in the 2011 Versus version of it it only featured Regis and Iedolas in the scene.
You can see in the top image from the 2011 Versus trailer Regis was the only one seen in this shot, plus he had the Engine Blade. Whereas in the 2013 shot under it you can see Clarus standing behind Regis, and the weapons around Regis had been changed as did the entire scene basically rerendered out.
The first ever gameplay for Versus for that grassy area (and actual gameplay in general) was also from 2010 for the footage of Noctis running to a gas station, running along a road in the desert, and the Behemoth in the street footage, and 2011 for the gameplay version of the invasion at night and the grassy area at day, not 2008.
Clarus in all likelyhood didn't even exist in 2008, neither did a majority of the cast in the final game let alone from 2011 version of Versus, none of the characters by Ferrari existed back in 2008. That CG render of beared slicked hair Clarus is from 2013 at the earliest, and in the behind the scenes feature for Kingslgaive you can see he was actually still going to have that bearded design in Kingsglaive even as late as 2015, but for some reason they decided to change it at some point between July 2015 and March 2016.
Though I feel like you can chalk up Clarus's face looking different to the same thing as Ardyn, Luna, Ravus and Iedolas's face and hair looking different from Kingsglaive to the game versions of them. We never actually see a game version of Clarus, but true that the Kings Tale does use a design that looks like a younger version of his 2013 design.