Just one thing: It is heavily implied that the Thalmor and the Dominion are very weak after the Great War and would unlikely win if the Empre stands united. They were the ones behind the Civil War IIRC to weaken the Empire. They talk big to seem more powerful than they are.
The Thalmor were in a stronger position than the Empire at the time of the signing of the WGC. This is evidenced by the terms of the WGC, but also by the fact that the major battles took place within Empire territory. Summerset Isle is still a stronghold, Elsweyr is flourishing and Valenwood has order for the first time in a very, very long time. By contrast, many of Cyrodiil's monuments and cities have been raised and wrecked, Hammerfell had to
recover provinces from Thalmor occupation and Skyrim is now deep into a brutal civil war.
The main issue the Thalmor has is that of population. However, this is a problem shared by the Empire. The Empire tried to buy time to breed and train with the WGC. However, the civl war in Skyrim has made that difficult, as well as the unsteady High Council.
EDIT:The Orc comment was to the guy saying orcs would be slaughting other mer.
I did hear some thalmor saying how they would ally with whoever won the war anyway, can't remember who said that though. I still maintain that the best interest for the people of skyrim is stormcloak leadership with the dragonborn in a position of power.
It would be a limited measure unlikely to hold up against a direct Thalmor assault. Skyrim would be in a much better state than Cyrodiil and in a less precarious position than High Rock too, but should the Thalmor attack either of those provinces or Hammerfell, it would only be a matter of time before it was Skyrim's turn.
Moreover, any alliance of men would be extremely unlikely in the aftermath of a Stormcloak victory. Should the Thalmor attack Cyrodiil, neither Hammerfell or Skyrim would have manpower or will to defend it. Both the redguards and nords have suffered large losses of life and diverting forces to Cyrodiil would mean weakening the defenses of Hammerfell and/or Skyrim. Of course, that's saying nothing of the bitterness and mistrust between Cyrodiil and the Stormcloaks as well as Cyrodiil and many redguards. No Imperial general would take orders from Ulfric's men on their homeland. Ulfric himself would not submit to being ordered around by the Empire, regardless of where they were.