I too have often wondered why he has been relatively incapable of providing any divine intervention for his people.
...because he provides almsivi intervention instead? Sorry, I had to.
Anyway, big YES to CHIM being silly. I also don't think Vivec really has it. Where's the proof? Actions speak louder than words, and seems to me he hasn't done anything to prove he has achieved that "status of being", or whatever.
Also agree with the "Tribunal did squat" line. I tried to calculate the monetary cost for an NPC to assault Dagoth Ur successfully. Let's see, with a faction rep. of a zillion, Vivec should have been able to have a disposition of at least 100 with all the Temple enchanters. With a few exquisite pieces of jewelery, he could have made some powerful enchantments (I'm thinking something that Calms Humanoid on Target, 50 ft. explosion, while also absorbing enemy health) for about 100,000 septims. Seriously, god powers aside, you can win if your rich! He must not have wanted to win.