Try an earlier save. This worked for me when on a playthrough every Imperial character(patrols, soldiers, guards) randomly decided to attack me onsite. 

Depends on the build I'm playing but typically I focus on combat skills. I'm also going to echo some other people here and say that levels 1 - 20 are also my favorites levels. sometimes I'll use a mod to slow leveling(sometimes to a crawl) for low level builds or just when I feel like I want things to go slower. 

I'm not saying it's a good thing but it's a good way to keep the empire busy while the Thalmor rebuild their forces and makes it easier to conduct acts of espionage throughout the empire because they can move around freely.

Entirely convinced the ban on Talos worship has more to do with the Thalmor trying to stir up internal strife in Skyrim(possibly Cyrodil as well) to weaken the empire. 

Yeah assuming any power in Akavir is in a position to send an army to Tamriel(Akavir is a divided landmass with warring factions) why wouldn't they wait until they could just march over a weak enemy and maybe take all or most of Tamriel.