With Vulcans and Romulans having a shared history, it's curious that the classic Vulcan-isms have no parallels in Romulan society - such as the Vulcan mind meld, the Vulcan nerve pinch, or even Pon Farr. (Correct me if I'm wrong.)
Are there any examples of Romulan telepathy? "Nemesis" has Reman telepathy, of course, but that begs the bigger question of where the Remans fit into the offshoots from Vulcan. Were they just the locals in the solar system the Romulans settled (who also just happened to have pointy ears and telepathy like Vulcans), or were they originally of Vulcan? Genetic divergences like that immediately conjure up images from "The Time Machine," of course, but there doesn't seem to be an in-universe explanation for why the Romulans don't have basic abilities we associate with their Vulcan relatives.
Beyond being green-blooded, the connections between Romulans & Vulcans seem superficial at best, even though reunification is seen as such a crucial issue. In the divergence, it looks like the Remans took all the cool powers with them, but still ended up under the whip of their Romulan kindred. "Live long and prosper" is not the Romulan way.