[Radek]

I think it was only luck. I have tried the Gold Digger trait several times and I haven't seen any difference between having it and not having it.

As to the pixies and ratlings. It's a curse of all games. You are offered trucks of races, which supposedly differ each other, but they differ only in the very beginning of the game. A few levels up and all differences are gone forever.
There is only one race in W&W, which differs from the remaining races - an elf. The Quick Learner trait is a never vanishing advantage. All other "race traits" become invisible soon. Even the Mana Seed (Omphaaz) and Dodge (Pixie) traits become unessential at higher levels.