You've said that you see stealth as the domain of both thieves and rangers, and that you see hiding to be more of a thief thing while stalking was more of a ranger thing. If we are to define stalking as movement while hidden then SLIP would have to be a stalking ability, and I'm wondering if you're intent on keeping it as a thief-only verb. Last I knew it was one of those verbs that was up to have the calcs reviewed and I thought this would be a good time to petition to get it opened up to Rangers.
-Teeklin