Finding a cold fusion reactor in Toronto with a Tritium watch from the 1990s would not work. Tritium is detected via the beta particles (electrons) it emits, which can't even penetrate a sheet of paper.
The painting in Pelia's possession is The Concert by Johannes Vermeer (1665-66). However, this painting was not stolen from the Louvre. It was stolen from the Isabella Stewart Gardner Museum in Boston, Massachusetts, in 1990.
Noonien-Singh and Kirk are shown arriving in Vermont, however they wouldn't have been able to cross over the border from Canada because neither one had ID.
This is explained when they are first talking to Pelia and Noonien-Singh clearly states they had to bribe a border guard.
Noonien-Singh and Kirk comment on a sunset on Harbourfront in Toronto, but they looking are southeast. So technically it was a sunrise.
If the Vulcans of the altered timeline have little to no contact with humans, how does Spock exist?
In the car, while having a conversation about names, Kirk says "Sam is his middle name. Most people call him George", clearly using present tense. Earlier, it is explained that Sam is already dead in his universe.