I think its unfair to say that anything a Stormcloak supporter says is good about Ulfric or anything that counters an accusation against him is somehow automatically wrong.
First of all, he killed Torygg because as Balgruuf put it "He thought it was only only way to make his point", which is: Skyrim is weak in its current position, and its the Empire that made it so. Besides, Torygg, while he apparently respected Ulfric greatly, he was too attached to the Empire to declare independance.
And the Thalmor, according to the Concordat, have free roam in the Empire to scour Talos worshippers, so Stormcloaks or no, they had presence to some degree in Skyrim. Although, of course, the Stormcloak rebellion have brought a greater presence of Thalmor to Skyrim.
In the end, Stormcloak win or Imperial win, it doesn't make much difference. Both are wins for the Thalmor.
Imperial win: Thalmor have access to all of Skyrim, to scour and destroy Skyrim's manpower as they please.
Stormcloak win: Empire is weaker with Skyrim independant.
Dont get involved: Best Thalmor solution, both Skyrim and Imperials waste manpower fighting each other for years.
So in the end, it doesn't matter. Hope you feel fufilled with your endless back and forth bickering.