I'm willing to bet the Rune Mage's other two talents deal with something related to the Might and Mind runes, making it a different kind of unit for each class I.E. Firebolt doing massive damage with a high amount of might runes.
I'm pretty confident at least two of the Faun's talents involve A: Forcing the targeted troop to sleep and B: Causing nightmares to sleeping troops.
Side note: This is just a hunch but I think the Ghost-Pirates' ability "Avarice" summons an extra chest randomly on the battlefield. You can see on one of the screenshots in the battle log something along the lines of "Ghost-Pirates spot a chest on the battlefield!" or something, and also there's a chest model that you typically only see when the pet dragon digs there. Link:
http://www.gry-online.pl/S055.asp?ID=186381
One thing though, I think it's a tad redundant that we're getting stone wall as a spell while the pet dragon essentially has the same spell. I hope one doesn't completely outclass the other, and hopefully they both have different tactical uses (especially since I already think stone walls are sort of underpowered).