Question on the stutter: Did your internet browser have hardware acceleration enabled? If it didn't, enabling that usually fixes that.
Walk audio: Hmm. I'll have to have a think on that.
Pick-ups: Pick-ups in general are getting an overhaul (working on it now, actually) and there will be a little inventory in the top left of what you've picked up.
Widdershins: It means counter-clockwise. :) I firmly believe more people should use this word.
Tiny targets: Hmm. That's valid. We're in the middle of re-doing the sprites for the sensors, so we'll keep that in mind when designing it.
Glass Colors: The whole tutorial is being reworked, so already on it.