For the Hivers, just lookup Niven`s Ringworld* and substitute Hiver for Pupetteers.
Manipulators All the Way, All of them.
If you read Marc Miller's comments in the AM Hiver (#4?) he says specifically that Hivers are not puppeteers. They may have similarities, but if you play them straight out of Niven, then you may miss the point.
I concur with the original posting about how cool the K'kree are. Truly not just another funny guy in a furry suit.
I find the best way to get into the K'kree mindset is to imagine how I feel on Christmas morning, with my family all around me and the smells of good food filling the house. That is what I imagine a Steppelord in the midst of his family, on his planet would feel like. Then to raise the righteous anger and indignation that I imagine a Steppelord confronted with Gnaak must feel like, I imagine that my X-mas morn has been disturbed by a gang of cannibalistic, necrophillic, door to door salesmen who really want to come in! At his most reserved the Steppelord will forbid entry of the Gnaak to his domain. At his least reserved moment, he will not think twice about slagging the Gnaak planet to glass, so that in a thousand years, the sons of his sons can reseed and repopulate the now cleansed planet.
Truly it is the good GM who can make the K'kree a credible and subtle threat to the players.