I just finished watching Enterprise
- 2x14 - Stigma
and was thinking about the "minority" of touch-telepaths that existed at the time in the 22nd on Vulcan. Despite the Vulcan High Command's Dictatorial Rule (Arguably a Romulan Plot to overthrow the Goverment and bring about Reunification their way...), being a Mind-Melder wasn't something that could be determined from Birth (As all Vulcan's were logged in the genetic database, and Soval (A high-ranking member) was capable of Melding himself and had escaped detection till just before the shift caused by the Kir'Shara.
I've always assummed that all Vulcan's had the ability to Meld though to differing degrees. Some might not have even been aware of their potential and it just lay dormant. The stigma associated with being a melder obviously made being open to or indulging oneself in the practice less than desirable. But afterwards with Sarek himself known as a melder, touch telepathy became a more wide-spread ability in possession and practice.
Of course, just like with Vulcans, Betazoids exist with varying degrees of Telepathic Talents.
We've seen evidence of a Human/Vulcan Pairing in Spock and a Human/Betazoid pairing in Deana Troi.
Half-Betazoid Humans tend to be Empathic with some low Telepathic Talents yet only with those that they are strongly connected to emotionally.
So cross two Telepathic Species and what happens... what would the result of a Vulcan/Betazoid paring bring to the table in terms of Telepathic Talents.
Some like Lwaxana Troi are very powerful (Did she use telekinesis at one point?)
Then you've got others like Rennan Konya who is Betazoid but lacks any real telepathic ability instead reading the motor cortex of others.
I'm just trying to get a handle on the possibilities. I guess I'm looking at best guesses unless this has already been done in the books somewhere.