Certainly the evidence leaves open a wide range of possibilities.
I like the idea of Vulcans making do with just a single name, even if this creates some practical problems for populations larger than a hundred... There's a nice bit on it in Dillard's The Lost Years
, where the long-out-of-the-loop ancient Vulcan mage is amused by the fact that Surakians still haven't run out of names in the S***k format.
OTOH, I like Duane's take on Romulan names, and I'd like to think it extends back to Vulcan names as well. That is, there are multiple names, but they are steeply hierarchial, far more so than our practice of given names and surnames. "Spock" would be the one to be used in public. "S'chn T'gai" could be reserved for clan/family ceremonies. And there could be Duanesque secret names, with strong magical connotations on how knowing the name gives one power over the person; the superficially rational Vulcans would be doubly motivated to keep those names from becoming public knowledge.