My understanding is that each race views the Aedra in specific and unique fashions, based on the begining of the world and wars between Men and Mer.
However to stop this from getting to far into lore, we still don't know why Alduin, who / whatever it is is in Skyrim.
The videos have the voice over saying they're back, that legends spoke of them returning when Nords spilt their own blood, that one can stop them.
That is all we know now.
It makes no mention to world eating, the devs have passed comment that dragons may be destructivem and randomly so in their travels.
This however is not saying they seek to eat the world, just that they are attacking people for some reason.
So we don't know which one is really Alduin(Akatosh or the Akaviri leader). Or are they all Aduin at the same time?
I'm not that steeped in lore..... why does Alduin want to eat the world? Why can't he eat the moon or something, that should keep him full. So is Dagon the rightful owner of Nirn or something?
The Nords are mixed up from ages ago, they don't despise / fear Lorkhan as most races do.
Rather they venerate him in the form of Shor.
Alduin is / has been a varient of their enemy the Mer, and also the rival of Shor / Lorkhan, Akatosh.
They see Alduin as a destroyer and a genitor.
The Genitor maybe from the fact that he gave himself to create Nirn.
The destroyer for he is both more elven in spirit ( their ancient rivals ) and the opposite of Shor, their more patron Aedra / daedra.