Kip was created mainly as a chance for me to expand my role-playing repertoire, allowing me to play a halfling for the first time. This explains why the little bugger is fun-loving, loves thrown weapons, and is excellent at hiding, moving silently, climbing, and the like... typical halfling fare.
But with Kip, I'm trying to do more than simply offer a bit of comic relief - as opposed to my two other, more serious characters. Sure, the little guy contrasts so much with the others that I have to play him - if only to prove to the rest of you that I'm not some gruff, old guy bent over a keyboard scowling... but I'm capable of running jokes ("Aaaahhh! Demon-halfling!"), hilarious antics ("Aaaaeeeeiiii!"), and good interaction ("Aaaaeeeiii!" <padapadapada> "Aaaaeeeiii!" <padapadapada>).
So young Kip ends up being a closet klepto with a fun-loving attitude and a tendency to get into trouble. And though he seems mercenary, he has no real love of gold or jewels. Rather, he enjoys adventure, flirting with the ladies, and - most especially - daggers.
And to explain his tendency to stealing... um... taking... no... borrowing things without asking, the halfling hardly realizes that he is doing it. Very rarely is it a conscious choice when he pockets someone else's valuables - or non-valuables. In fact, if he were to be asked to steal, he'd probably be offended or claim not to know how to.
Playing the Kipster is fun, and I hope that is enjoyable for some of the rest of you - especially the ones with the misfortune of dealing with him.