So, the UESP wiki has the symbol that was displayed at the very end of the trailer listed as the Akavir banner. Ive seen this in many places in elder scrolls game so is this really true?
http://www.uesp.net/wiki/Lore:Akavir
Not quite. Thats the Imperial sigil, which is influenced by Akaviri motifs, but its not directly Akaviri.
A faux invasion that would ultimately result in a stronger and more unified Nirn that is more capable of resisting invasion from Oblivion must be in his best interests as Nirn's second founder and primary Divine?
I don't think he is that concerned about Nirn weathering Oblivion invasions. Honestly though, theres no way of knowing at the moment. I think that your particular story goes against his character as I understand it, but Beth can disagree and/or interpret him differently. I'd say that his periodic distraction of Nirn is a possible storyline though.