As for T'Pol that was meant to be revealed in the series that never was, so not sure how 'canon' that makes it.
Since it was never revealed, it's not canon in anyway. Which is a shame because back in Enterprise's first season I insisted T'Pol was a Romulan and had a bunch of arbitrary and in some cases idiotic theories to back up the claim. I was laughed at and mocked down in the Enterprise forum, so it would have been nice to be vindicated. Ah well, it was eventually revealed that Vulcan's government was being manipulated by Romulans during Enterprise, that's vindication enough.
Sector 7 wrote:
An entire movie [arguably not a successful one] was devoted to Romulans in Nemesis.
Nemesis was more about Shinzon and the Remans. Romulans were only featured in it, the movie wasn't about them.