Board Thread:Lore Discussion/@comment-95.94.124.138-20130922100323/@comment-1470368-20140708173420

Nord race not required. You can even have done questionable deeds & have questionable views.

All that is needed is to die in battle, die in Skyrim, and believe in Talos.

Tullius can be found in Sovngarde if he's killed...so it's really no question that he's all of the above (including his true belief in Talos).